Jefferson Jackson

:For other uses of the term "Firestorm" see Firestorm (disambiguation).
:For other uses of Captain Cold, see Captain Cold (disambiguation).
Jefferson "Jax" Jackson (born September 12, 1993) is a mechanic and a former member of the Legends. After the death of Ronnie Raymond, he took his place as one half of the transmuted and conjoined meta-human called Firestorm alongside Martin Stein. Jax was then recruited by Rip Hunter on a mission to take down Vandal Savage; although Jax was initially unwilling to join the team, Stein, who was desperate to become a time traveler and knew that he couldn't be separated from Jax for long without his powers becoming unstable, drugged him and forced him to come along. Despite joining the team against his will, Jax later grew to like being part of the team, and he began to act as the mechanic of the Waverider as well as a member and the second-in-command of the Legends, a group of individuals dedicated to protecting the timeline from time criminals.
After the death of Martin during the Earth-X invasion, Jax took a leave of absence from the team with their blessing. Five years after leaving the Legends, Jax married Alanna Jackson and they had a daughter, Martina, named after Martin. Later, in order to help Ray and the Ex-Legends save Mick Rory's children, Jax became the new Captain Cold.
After the 5 years, he re-allied with the Legends in order to stop Mallus.
==Biography==
===Original multiverse===
====Early life====
Jefferson was born in September 12, 1993 to James Jackson and an unnamed woman.
Two weeks after his birth, Jefferson's father was killed in an IED explosion while serving in Somalia, hurting both him and his mother. He also watched many horror movies with his mother.
As a senior in high school, Jefferson was a promising football quarterback and a 4.0 student. On December 11, 2013, Jax led his school to a victory at the game while scouts from colleges watched from the stands. These scouts were instantly impressed by his performance on the field, and his coach told him that he was talented enough to go to any school he wished. Despite that, Jefferson wasn't very popular and frequently got into fights in school. Shortly afterward, the S.T.A.R. Labs particle accelerator exploded, creating a huge wave of dark matter that spread over the city. Upon seeing the wave of energy approach, the attendants of the game ran for their lives, causing a stampede that held up one of Jax's injured teammates who relied on crutches to get around. Jax aided his teammate to safety inside of the high school, but before he could close the doors, he was struck by the dark matter at such a high speed that he was thrown backward into a wall, knocking him unconscious and slamming him into the floor.
Jax woke up in the hospital and quickly learned he could never play football again because of a permanent injury to his knee caused by the explosion. Because his family couldn't afford college and his only hope of attending college was on a football scholarship, he was ultimately forced to find a full-time job as a mechanic to support himself.
====Becoming Firestorm====
Two years later, Jax was approached by Barry Allen and Professor Martin Stein at the auto shop where he worked. Barry and Stein had sought him out because the dark matter wave from the particle accelerator explosion changed his body's molecular structure in a way that made him one of two perfect matches to Stein, who, due to the death of his literal other half, Ronnie Raymond, was dying as a result of his powers becoming unstable from a lack of merging and needed to find a new partner. When he went to S.T.A.R. Labs to learn more about it and met Barry Allen's team, he refused to merge with Professor Stein and become a superhero, a decision that caused him to be berated by Caitlin Snow, Ronnie's widow, for his supposed inability to take responsibility, as she did not know about his family's financial situation and had assumed that he blew off college out of laziness despite his perfect grades. Caitlin later showed up at his auto shop and apologized for her behavior, explaining that her missing husband, Ronnie Raymond, became a hero as Firestorm and saved the city from the singularity, inspiring Jax. They are attacked by Dr. Henry Hewitt (The other candidate to become the new Firestorm) and escape to S.T.A.R. Labs, where Jax agrees to merge with Stein to save him resulting in the two becoming the new Firestorm. When Hewitt is wreaking havoc on Jax's old football field, he teams up with the Flash to stop Hewitt and starts to get used to his new superhuman abilities. Afterwards, he and Professor Stein go to Pittsburgh to train on Firestorm's abilities similar to Ronnie.
====Aiding Rip Hunter====
In January 2016, Jax and Martin Stein are still in Pittsburgh, where they are up against a criminal at a chemical plant as Firestorm. Stein tells Jax to be careful, as 83% of the chemicals are flammable, however, Jax still shoots fireballs all over the place. While Firestorm does defeat the man, Stein is still upset that Jax doesn't listen to him, Jax tells him to stop treating him like one of his "snot-nosed undergrads" when they are intercepted by Rip Hunter. Jax and the rest of Rip Hunter's recruits woke up on top of a building where Rip informed them of the impending threat of Vandal Savage's conquest of the world and a chance to join him. Later, Jax and Stein discussed Rip's offer where Jax was firmly against it while Stein relished the opportunity. However, Stein drugged him and took him on Rip Hunter's mission anyway.
=====Exploits in 1975=====
Jax woke up as the team is en route to St. Roch in 1975 and was angry with Stein. Jax was left behind in the Waverider when Chronos attacked. Jax merged with Stein and provided cover for the team to escape. After learning of Rip Hunter's status as a rogue Time Master, Stein and Jax discussed leaving, but Jax had a change of heart because he likes being part of a team, reminding him of his days as a football star.
They tracked down Savage to Norway. However, Savage recognized that they weren't terrorists and a huge fight broke out. Firestorm fought off Savage's criminal allies, but Ray Palmer left a part of his A.T.O.M. Exosuit behind, altering history. Jax accompanied Stein and Sara as they meet with Stein's younger self from 1975 in order to track down the lost part. They stole young Stein's alpha-particle tracker and used it to take Ray's tech back from Savage's minions, but young Stein tracked them back to the Waverider. After the younger and elder Steins got into an argument, Jax consoled the elder about how arrogant both himself and his younger self are, but also how selfless and intelligent he has become. After the younger Stein was escorted off the ship, the team was contacted by Snart, who had been captured by Savage. Firestorm took down Savage and the team escaped. While Carter Hall and Kendra Saunders went to finish him off with the Amon Dagger, the rest of the team held off Savage's forces. However, Savage managed to get the upper hand and killed Carter and wounded Kendra forcing the team to retreat back to the Waverider. Afterwards, Jax and the rest of the team reaffirmed their commitment to defeating Savage in memory of Carter.
While stuck in Leipzig in 1975, Jax was tasked with fixing the jumpship which was damaged during Chronos's attack. Leonard and Mick were getting bored on the Waverider so they convince Jax to fly them to the Central City Museum to steal the Maximillian Emerald to give it to Leonard's father. After Rip and Sara were captured trying to rescue Carter's body, Jax flies the jumpship to rendezvous with the team at the Grayhill building. Later, Jax was present at the funeral they put on for Carter and Aldus.
=====1986 and the Cold War=====
The team's next mission took them to 1986 to break into the Pentagon to steal a file on Savage's current whereabouts. As Firestorm, he was tasked with creating a diversion by cutting the power, however he accidentally tripped the alarm, but they succeed on getting the file. The file directed them to the Soviet Union. After Time Master Druce set a trap for Rip, he is rescued by Jax, Stein, and Mick but Jax is wounded. Stein and Jax get into an argument where Jax is angry that he has to take all of shots, was unwillingly brought on the mission, and was forced to leave behind his life and his widowed mother in 2016.
On board the Waverider, Jax felt Stein's fear as he was being held and tortured in Koshmar. Jax and Kendra use the link between him and Stein to send him a sign by cutting a message on his arm, which would then appear on Stein's saying that they were coming. Frustrated with being left out of the rescue efforts, Jax and Kendra convince Rip to let them help. Kendra flies Jax into the prison and he cuts the power to the locks causing a prison riot. After Stein is unwillingly fused with Valentina Vostok to create Soviet Firestorm, Jax inspires Stein to break the merge. After Vostok began to destabilize, they retreated to the jump ship. Later he and Stein make amends and Stein expressed his gratitude to have Jax as his partner. After another attack by Chronos, the Waverider is hit and the team is stranded in 2046.
=====Detour from the mission=====
After the team arrived in Star City of 2046, they are attacked by the Green Arrow. They retreated to the ship where Jax diagnosed the repairs that are required to get the Waverider operational again. He wanted to have Kendra's help in repairing the engines, and started to flirt with Kendra as they make repairs. Stein was able to deduce from his psychic link that Jax has a crush on Kendra and tries to deter Ray from getting close with Kendra. Stein's effort backfired, upsetting Jax but Stein told him to have more confidence in himself. Later, Sara Lance went off on her own to rescue the Connor Hawke, but the team came in to save Connor, Oliver, and Sara. Back on the Waverider, Jax overheard Kendra turning down Ray and had second thoughts about asking her out.
While in the Temporal zone, the Waverider received a distress call from the Acheron. Jax, Martin Stein, Rip Hunter, and Mick Rory investigated the ship but were captured by time pirates along with Captain Eve Baxter. After Mick went to make a deal with the pirates, Stein was able to sneak aboard the Acheron and free them. Jax, Stein, and Baxter acted as a distraction while Rip activated the airlock sucking the time pirates into the vacuum of space. In the aftermath of the battle, the team decided that Mick was too much of a liability, so Snart volunteered to put him down.
=====Foray into 1958=====
The updated timeline data from the Acheron pointed to Harmony Falls, Oregon in 1958 as the next place to find Savage. Jax was put in charge of gathering information from the local teenagers about a series of murders. After meeting Martin and Sara during their lunch hour in a diner, he talked to Betty Seaver but some jocks tried to intimidate him. Betty asked him out for tomorrow night. On the date, Jax asked Betty about her ex-boyfriend Tommy, who went missing. Before she could say anything, they were harassed by guys from the diner and then a horrific creature resembling Tommy attacked them. After fleeing the scene, they were pulled over by a police officer. Jax pleaded to the cop to get Betty medical help but was kidnapped by the cop. Jax woke up inside Savage's Hall H wing and was given a dose of an Nth metal meteorite, mutating into a Manhawk. After Savage released him from his cell, Jax attacked Martin and Leonard but was knocked out by Sara. Stein and Gideon then synthesize a gene-therapy antidote curing the Manhawk mutation. He said goodbye to Betty and told her to someday get out of Harmony Falls. The Waverider was then attacked by Chronos again and the crew was forced to leave behind Kendra, Ray, and Sara in 1958.
In the aftermath of Chronos' attack, Jax and Stein found Rip but discovered that Leonard was taken by Chronos. Due to the attack, the Waverider's navigation was damaged so the ship touched down in 1960 instead of 1958. They picked up Kendra and Ray in Hub City. They then went to pick up Sara who had rejoined the League of Assassins, but due to temporal drift, she had become detached from her former self and captured them. After Sara and Kendra face a trial by combat, Sara refuses to kill Kendra but Chronos attacks the League. She convinced Ra's al Ghul to free the team and they all take down Chronos, only to discover that Chronos was actually Mick.
=====2147 and the rise of Savage=====
The team next traveled to the Kasnia Conglomerate in 2147 to stop Savage before his rise to power. Jax, Martin, and Ray gathered more information on the A.T.O.M. robot police force Kasnia uses to enforce order. After the rest of the team kidnapped Per Degaton, Jax suggested dropping him off in the Stone Age instead of killing him. In retaliation, Savage and Tor Degaton's forces surrounded the Waverider. Jax, Sara, and Snart held off the soldiers and A.T.O.M. robots while Kendra and Ray disabled the robot command center, but Sara got captured by Savage. After failing to kill Per Degaton on his own, Rip then exchanged Per Degaton for Sara and the team retreated afterwards, but failed to stop Savage's rise to power. Mick then informed the team of The Hunters who will now go after them since Chronos' mission failed.
=====On the run from the Time Masters=====
Hiding from the Hunters, the team touched down in Salvation in 1871, a fragment in time invisible to the Time Masters. After Leonard shot a member of the Stillwater Gang for fighting with Martin, the team got into a bar fight before Jonah Hex settled things down. Hex then demanded to speak to Rip about dealing with Jeb Stillwater. Ray, Leonard, Mick, and Jax went to arrest Stillwater, but Jax was taken hostage. Rip challenged Stillwater in a quick draw to free Jax which Rip won, killing Stillwater. However the Time Hunters arrived and a huge fight broke out between the Hunters and Rip Hunter's team. The team defeated the Hunters and Jax excitedly proclaimed victory. However, one of the Hunters warned of The Pilgrim, who Mick confirmed will come after their younger selves.
In Central City of 1990, the team first went to save Mick Rory's younger self. Mick tasks Jax with watching over young Mick. After targeting Sara Lance's self from 2007, Firestorm saves Ray Palmer's 2014 self from The Pilgrim but discovered her powers of temporal micro-manipulation. The team then switched tactics to abduct their selves as newborns. Jax revealed that he never got to see his father because he shipped off to Somalia before he was born. However, in Central City of 1993, Martin and Ray saw that his father had not shipped off to Somalia yet and retrieved Jax so that he could talk to his father. Then The Pilgrim showed up in 1993 to newborn Jax's empty crib. The team took the younger versions of them all to The Refuge where they learned a little of Rip Hunter's past. 
After returning to the Waverider, Jax was saddened that he didn't tell his dad about his fate in Somalia and about what he missed out on without a father. The Pilgrim contacted the Waverider to say she had taken James Jackson and other loved ones and threatened to kill them unless they turned themselves in. Rip counters the Pilgrim's offer by offering his younger self in exchange for the team's loved ones and younger selves. When the exchange of James Jackson for young Rip Hunter was made, the team attacked The Pilgrim. She managed to hold them off with her time manipulation powers until young Rip stabbed her in the leg and the team subsequently destroyed her. Jax then had one last conversation with his father telling him to be careful for IEDs while on his army tour.
=====Taking the fight to Savage=====
Running out of time to kill Savage, the team traveled to the only time they knew for certain where he was, 2166. Jax accompanied Rip, Ray, and Martin to make contact with the resistance where he offered a candy bar to a refugee child. After capturing Cassandra Savage, the Waverider was attacked by The Leviathan. Martin was injured in the attack and asked Jax to take care of the refugees. Once the team came up with a plan to take out Savage, Jax assisted Ray in modifying his exosuit to grow in size to fight the Leviathan, and monitored Ray from the Waverider as Ray battled the giant robot.
The team analyzed the Leviathan and determined that the technology it uses is more advanced than anything in 2166 and that Vandal Savage must also have been manipulating time. Rip decided to take Savage to the Vanishing Point for punishment before the Time Masters Council for messing with time. However, the ship's time drive had taken too much damage and Rip tasked Jax with fixing it. However, temporal radiation leaked from the time drive, causing his body and organs to age at an accelerated rate, but he succeeded in restoring the time drive. Martin then put Jax onto the jump ship to 2016 and deduced according to his theory of quantum-retro causality that the trip back to 2016 should reverse the side effects of the temporal radiation.
Jax arrived back in 2016 cured of his temporal ailments and enlisted the help of Martin. They scavenged Eobard Thawne's Time sphere for parts to the jump ship. After repairing it, he told Martin that his present-day self would be very angry for drugging him but that he was very thankful for Martin's decision to bring Jax along. Jax then time traveled to the Vanishing Point and arrived just in time to save the team from Time Master Druce's soldiers. Firestorm held off the reinforcements while the team figured out how to self-destruct the Oculus. Once Leonard sacrificed himself to destroy the Oculus, the team left the Vanishing Point.
Rip brought the team back to Star City of 2016 because Vandal Savage had been lost to history after taking Kendra and Carter/Scythian. After everyone tried going back to their separate lives, they met back in Star City at the spot where the Waverider dropped them off. The team then found a message from Kendra hidden in an old helmet in Rip's quarters leading them to Saint-Lô, France in 1944. The team then attacked Savage and rescued Kendra and Carter, with Jax discovering a new power of transmutation. Jax and Stein then tried to replicate the power but with no success. The team later figured out Savage's plan to undo time by detonating three Thanagarian meteors in three different time periods. Jax, Martin, and Sara went after Savage in 1975 while the others went after him in 1958 and 2021. After Sara killed Savage of 1975, Firestorm used transmutation to turn the meteor into water and prevented it from detonating. 
The team then rendezvoused in St. Roch of 2021 but the radiation buildup from the third meteor prevented Firestorm from transmuting it. Rip piloted the Waverider to fly into the sun with the meteor saying his goodbyes to the team. However, Rip angled the ship to eject the meteor and time jumped back 20 minutes and rejoined the team in St. Roch. He then offered the team to join him in protecting the timeline now that the Time Masters are gone. Jax and Clarissa have an intervention with Martin convincing him to go. They meet back in Star City where Kendra and Carter leave the team now that Savage is finally gone. Then, another damaged Waverider crash lands with a man named Rex Tyler from the Justice Society of America telling them not to board the Waverider.
====Protecting the timeline====
Sometime after encountering Rex, the Legends embarked on a mission to protect King Louis XIII in France 1637. Jax jumped off a palace balcony and merged with Martin in midair. Firestorm then fought off the attackers breaking Rip's rule of not using superpowers. After a time quake originated from New York City 1942, the Legends arrived there but Rip had Jax remain behind on the Waverider to repair the time drive. Later, the Legends tracked Damien Darhk to the Garrett Shipyard and engaged Darhk and his Nazi allies with Firestorm providing cover for the team. They rescued Albert Einstein's ex-wife Mileva Maric but could not disable the atomic bomb so they retreated. Rip then gave Jax a list of more repairs and modifications to the Waverider including a time scatter function which he told Jax was an emergency measure he hoped he would never use. Rip quizzed Jax on the Waverider's functions making Jax realize that Rip's constant repair requests were actually teaching him about the Waverider.
When in pursuit of Darhk's submarine, Rip realized the only way to stop the bomb was to collide it with the Waverider underwater so he used the emergency time scatter to evacuate the Legends. The time scatter sent Jax and Martin to medieval Tintagel, England 821. They acted as "wizards" for the king until he grew bored of them and ordered their beheading. However, Nate Heywood and Mick rescued them from the execution. After all of the Legends were back on the Waverider, Gideon played Rip's final message to them to carry on in his absence. The Legends returned to 1942 to ensure the Einsteins' protection, but were subsequently confronted by the Justice Society of America.
The Legends tried to explain their mission to the JSA but they didn't believe them and a street fight ensued. Firestorm was incapacitated by Stargirl's staff and The JSA easily defeated the Legends. They locked up the Legends at the JSA headquarters and later interrogated them before letting them go and told them to leave 1942. On the Waverider, the Legends voted Martin as the new Captain of which Jax doubted since he thought Martin was too analytical. Shortly after, Nate discovered that the JSA were going to die in their next mission so they returned to 1942. They infiltrated a Nazi nightclub in Paris and overheard Baron Krieger's plan but a bar fight broke out which ended when Stargirl arrived with the rest of the JSA and used her staff to knock out the club-goers. The JSA then agreed to work with the Legends to stop Krieger and retrieve the Askaran Amulet. After Martin deferred leadership to Sara and with both teams working together, they stopped Krieger and retrieved the amulet from the Nazis.
Amaya Jiwe of the JSA snuck on board the Waverider and knocked Jax out while he was in the engine room. Jax later watched Ray test out Nate's new steel powers in the cargo bay. When Ray and Nate blew a hole in the ship, Jax went to the engine room and rerouted power but was unable to repair the ship enough to save Ray and Nate from the temporal zone. Jax later patched up the hole in the ship while the rest of the team rescued Ray and Nate in Japan 1641. Gideon's diagnostics confirmed that his patchwork fixed all 36 compartments of the ship which made Jax realize there was an extra part of the ship he didn't know about. Jax and Martin investigated the compartment discovering an armory and a secret message from Barry Allen of 2056 that Rip kept secret.
The Legends then tracked down an aberration in 1863, caused by the biological weapon of a time pirate. When Union spy Henry Scott was killed by a horde of Confederate zombie soldiers, Jax and Amaya sneaked into the Collins Plantation to complete their mission. Jax was caught, so Amaya went to rescue him and the Collins slaves. Jax and Abraham helped the slaves escape a horde of zombies and let Collins die from the mistreatment. As they left, Jax joined Amaya and other slaves to watch the plantation go up in flames. Later, Jax and Amaya led the slaves to Ulysses S. Grant's camp for safety before returning to the Waverider.
A week later, they saw that Damien Darhk was 40 years after the JSA. The team teamed up with Obsidian in order to stop Damien. However, Sara discovered that Darhk had teamed up with the time traveler who had killed Rex Tyler and was a speedster, faster than Barry.
Then they observed a temporary aberration that had led them to the Wild West. Once there, they managed to rescue Jonah Hex from a hanging by the thief Quentin Turnbull. Jax, Ray, and Nate posed as members of the Treasury to enter Turnbull's home. After a quick firefight with superpowers, they decided to go to the cave where Turnbull was going to make his evil plan. There, they discovered that there was a dwarf star on the ground. When they all had to go into a terrifying battle, Jax watched as Nate was shot by Turnbull's gun. However, Jax and Ray were able to see how Nate slowed down an entire train loaded with dwarf star with his powers.
=====Dominator invasion=====
The team was later called to late 2016 due to an aberration caused by the arrival of alien life on Earth known as the Dominators. Upon arrival, Jax and the Legends met Earth-38's heroine, Kara Danvers, also known as Supergirl. Jax and Stein met with Barry and Oliver to show the 2056 message they found on the ship, which said they couldn't trust it, and Barry confirmed it by revealing what happened at Flashpoint to everyone. Firestorm along with the other heroes, except Barry and Oliver, went to rescue the president, but it was all a trap from the Dominators, who mentally controlled them to fight against Flash and Green Arrow. Firestorm and the others managed to return to normal, but some managed to escape due to Oliver Queen, Sara, Ray, John Diggle, and Thea Queen.
Upon discovering that the Dominators wanted to capture Barry, Jax and the heroes decided to protect their friend and forgave him for everything that happened. All the heroes fought valiantly against the Dominators and Jax took the bomb to destroy it, but he had no faith until Stein motivated him and managed to turn the bomb into water and saw how the Dominators escaped, giving the heroes' victory. Later, Firestorm and the heroes were honored by the government and celebrated the victory.
=====The Legion of Doom=====
The following days, Martin was too distracted by his daughter and Jax pressured him to tell. Jax worked as an infiltrator in an underground club with Sara and Martin, but Sara and Martin were kidnapped by Al Capone and Malcolm Merlyn, who shouldn't be around this time. Jax was worried about them, and was glad when they returned "safe and sound." Jax discovered from the cameras that Martin was a sprinter: Eobard Thawne. Jax alerted them and shot Martin with the anti-sprinter weapon, but Thawne was too fast and managed to beat him. Jax continued on the mission, but without being critical.
On the ship, the Legends learned that Rip's neurological system had been reprogrammed, and he now had another identity. Gideon told them that Rip had recovered a piece of wood before his disappearance, and the team realized that it could be a piece of Spear of Destiny. They also soon realized that the attack on the film set had caused another aberration, as the incident scared young George Lucas away from a film career, that is, Star Wars and Indiana Jones no longer existed, causing trouble as these films had inspired Ray and Nate, respectively, to pursue their fields of science and history. 
Jax realized that the movie was inspired by their lives and told Sara that they could find the first piece of the Spear. Jax realized that the movie was inspired by their lives and told Sara that they could find the first Spear piece. Jax and Sara saved the team, but they faced Thawne's gang until they were saved by Rip, who remembered a bit of his memory, but was kidnapped by Thawne, Darhk, and Merlyn. At the Waverider, Jax consoled Sara and promised to save Rip.
Discussing their next course of action, the Legends decided to head to Central City 2017, where Jax and Stein searched for Stein's daughter Lily, who helped them figure out how to use the Askaran Amulet while the rest tried to figure out the identity of the speedster. After Lily discovered it was an aberration, Jax encouraged Stein to reconcile with his daughter. The Legends deduced that the speedster was from the future, and Nate later suggested that it could be a temporary aberration of time that would explain why there were no records of him and why he wanted to rewrite reality. Stein later identified him as Eobard Thawne, an enemy of The Flash who ceased to exist when his ancestor committed suicide to stop him, theorizing that he had been prevented from being erased due to his connection to the Speed ​​Force. Nate then suggested that he had to keep moving, so time wouldn't catch up with him, meaning if they could catch him in one place, he would cease to exist.
In the Waverider, Sara and Jax discover Gideon's time warp in 1776. The Legends discovered that George Washington had been assassinated. Jax and Martin reveal to Sara that they have to get Washington out of the meeting. Jax watched as Rip shot Sara, which made him angry. Jax took her to the med bay and wanted revenge on Rip for what he did. To rest, Sara left Jax in charge, but he didn't know how to be captain, but Stein encouraged him to lead. Jax discovers Nate and Amaya on the Waverider and reveals to them that they have to go out and discover Washington to avoid the mission. Locked in the ship, Jax, Ray, and Stein realized that Rip and his soldiers were attacking them. Jax took it upon himself to confront Rip until they managed to eliminate all the soldiers. Jax chased after Rip with a gun to kill him, but was calmed down by Sara, who managed to wake up, and convinced Jax not to kill Rip. Upon returning to the ship, Jax and Sara talked about being a captain. Soon after, the Legends celebrated Christmas as a family.
The Legends traveled to the year 3000 only to find the Doctor Midnite killed by Rip. The team discovered that another part of the Spear is in medieval England, so they traveled to 507 to find it before the Legion of Doom. The group arrived at the Court of Camelot, where they met King Arthur, and surprisingly they met the former JSA member, Stargirl, who had become Merlin. Jax and the team discovered that all of the JSA members were awarded the pieces of the spear by Rip and were split over time to prevent the pieces from getting together. The Legends discovered that Rip and Darhk also arrived by spear. Jax found out that Martin stole a futuristic device from Midnite, which made him angry. To free the knights from Rip's mind control, Jax and Stein used the device on Mick to successfully disable mind control. Upon capturing Rip and obtaining a piece of the spear, Jax spoke to Rip in his cell and warned him that if he did anything to his friends, he would kill him.
When Rip escaped, Jax had to shut down the Waverider to prevent his escape, but accidentally the Legends were stranded on the ship. To help Rip, Mick advised them to enter his mind to remove the mind control. Jax and Sara managed to enter Rip's mind and saw that his controlled mind was full of Vandal Savage soldiers, and there were also evil versions of them. Jax and Sara were helped by Gideon, who in Rip's mind was a human. Jax, Sara, and Gideon found Rip scared because he couldn't get over his fears. To get out in time, Jax faced the evil Legends, but Rip managed to overcome his fears, and they all escaped together, making Rip regain his memory. Now to get the last piece of the spear, the Legends along with Rip had to find Commander Steel.
The Legends managed to find Commander Steel in 1970 at the NASA base. The team learned that the last fragment was on the moon. Jax, Mick, and Stein teamed up with mission control to infiltrate and help Ray get to the moon. While Stein and Rory distracted everyone by singing, Jax managed to get Ray to safety. After reuniting on the ship, the Legends locked Thawne in the cell until he escaped, but the Legends obtained the last piece of the spear.
=====Fight for reality=====
To complete the Spear of Destiny, Jax and the Legends infiltrated Vanishing Point, which was the lair of the Legion of Doom. Firestorm turned the traps into candy, and the Legends got all the pieces and managed to escape from the Legion. After weapons the Spear, the Legends could not destroy it, so they had to travel to 1916 during the First World War to get the blood of Jesus Christ, and thus they could destroy the Spear.
After discovering that the Legion recruited Snart before he joined the team, Jax became upset that Rory might betray them, which made Mick angry. Jax stayed on the ship and helped the others escape, but Mick betrayed his friends by joining the Legion. Jax and the team were still upset by Mick's betrayal, but Rip confirmed that they were the ones who betrayed Mick for not trusting him and had to get the Spear back, but it was too late because the Legion had already changed reality.
In Doomworld, Jax had no memories and worked for Thawne. Jax was Stein's boss, who worked on a machine for Thawne and Jax treated Martin very badly. After the Legends infiltrated S.T.A.R. Labs, Jax regained his memory and joined them. Jax and the team hatched a plan to return everything to normal, but they left Mick, as he might betray them again. The Legends infiltrated again and Jax tried to apologize to Stein, but they were interrupted by the Legion, who were tipped off by Mick. The Legends received back Mick and Darhk, Merlyn, and Snart revealed themselves to Eobard. The Legends faced the Legion and the guards. The Legends managed to win, but Snart killed Amaya and Eobard destroyed the Spear. With no other options, the Legends now had to find another way to fix the mess.
After meeting Rip on the Waverider in tiny form, the Legends managed to enlarge it and thought of one last option to fix everything, which was to travel back to 1916 to get the Spear before the Legion steals it, but they run the risk of encounter their versions of the past, which would cause something cataclysmic. Jax and the team followed through on the plan, but were discovered and teamed up with their other versions to save the world. The Legends of the past and of the future united to face Merlyn, Darhk, and Snart. When Stein was going to die, the Jax of the future sacrificed himself for him. Jax was reunited with his teammates, and they were shot down by Thawne and his temporary remnants. Sara successfully managed to eliminate the Spear and Black Flash murdered Thawne. The Legends managed to fix everything and went to the ship to leave. The Legends prepared to take a hiatus in 2017 in Aruba, but accidentally fell in Los Angeles, where they saw various things from times past in the present, and realize they damaged the time.
====Fixing Anachronisms====
=====Return to the Legends=====
The team had to separate because Rip created the Time Bureau. Jax dropped out of college to try to get back on the team. Jax went to Martin's house and was surprised to see that Lily was pregnant. Jax and Martin saw the Waverider return and agreed to help them catch Julius Caesar in Aruba. By capturing him, the Legends took him back to his time, but caused a great aberration due to Nate accidentally leaving his Roman history book at the hands of Caesar. Firestorm and the Legends rescued Ava Sharpe, and together they stopped Caesar's invasion. Jax managed to convince Caesar to keep fixing anachronisms.
Jax and Ray woke up Nate to see how the Time Bureau devices worked. The Legends traveled to 1870 in the circus of P.T. Barnum for an anachronism due to a saber-toothed tiger being in this era. Jax and the Legends planned to use Ray's shrinking beam, but they accidentally made the tiger more giant. As they played cards, Jax and the others were delighted to see that Amaya returned. Jax, Ray, and Nate went out for drinks, but Nate accidentally revealed his powers to Barnum, causing Jax, Nate, and Ray to be locked in the circus. Jax and Ray told Barnum that they couldn't use their powers, so they had to pretend to be combined twins until the team managed to rescue them and fixed the timeline by giving a circus show.
The Legends traveled to 2042 to help Gary Green on a mission. Jax and the team met Zari Tomaz, a metahuman and hacker who escapes from A.R.G.U.S. and Jax and the team had faith in her, so they decided to help her protect herself from the "water witch". The Legends helped Zari infiltrate A.R.G.U.S. to rescue her brother, but this was a trap of hers. On the Waverider, the Legends engaged Ava Sharpe in a ship fight, which they managed to escape and helped Zari and Ray defeat the water witch, who turned out to be Kuasa. The Legends accepted Zari into the team.
While they were at Ray's presentation on trust, Zari already knew what everyone was doing and revealed that Jax had a crush on her. Jax saw that Martin was hiding something and believed that he worked for the Bureau, so he met with Mick to find out what was wrong. Jax and Mick discovered that Martin wanted to go to 2017 to see the birth of his grandson, so the duo helped their friend to go on the Jump Ship to 2017. Jax, Mick, and Martin arrived in time to see the birth of Lily's son, Ronnie, in honor of Ronnie Raymond. Firestorm and Mick reunited with the Legends in 1988 to help young Ray on Halloween.
=====Attempt to separate Firestorm=====
Because he wanted Stein to be a good grandfather, Jax asked Ray for his help in creating a serum to separate Firestorm. Jax and the Legends agreed to help Rip catch a supposed vampire in 1895. Jax and Ray were discovered by Martin, who was upset that they didn't tell him. Jax and Ray contacted a member of Team Arrow, Curtis Holt, to inspect the vampire's blood and were shocked to discover that it was not a vampire but rather Damien Darhk's blood. 
Jax and Ray communicated to the team that the Order of the Shrouded Compass planned to revive Damien and have Rip tricked them. The Legends managed to get out of the ship and went to confront a revived Damien Darhk alongside his daughter, Nora. The Legends discovered about the existence of the demon of time, Mallus. Everyone got mad at Rip and turned him over to the Bureau. Jax and Martin agreed to help each other to try to separate Firestorm.
In one attempt, Jax and Martin accidentally switched bodies. Jax and the Legends traveled to 1937 to avoid a movie studio war over actress Helen of Troy, but Jax stayed on the ship. Jax discovered that Stein liked Hedy Lamarr, but Clarissa let him. Jax and Stein discussed that if they merged they could cause an explosion that would destroy the ship. Stranded on the ship, Jax accompanied the Legends to protect Helena from Damien and her daughter. Jax and the professor protected Hedy. Jax and Stein eventually merged bringing them back to normal, but Jax was now temporarily on Martin's mind and helped the professor defeat Nora. Shortly after, Jax and Martin said goodbye to Hedy and Jax made fun of Stein for Hedy's kiss.
Jax and Professor Stein were still researching how to create the serum. Jax and the Legends spotted another anachronism in Vietnam, 1968. Jax returns to the ship and sees that someone ate his pecan pie, but discovers that Stein brought various figures from stories like Isaac Newton and Galileo. Angry, Jax went to the med-bay to take care of Sara. Jax and Stein saw that the anachronism was at level 10, so they return to Vietnam to stop President L.B. Johnson's escort to prevent them from being attacked by Gorilla Grodd. Jax saved President Johnson and his soldiers from planted mines and as a thank you, Johnson gave him a "top secret," the recipe for a famous pecan pie from his wife Lady Bird Johnson. After fixing the anachronism, Jax and the Legends celebrated Sara's return by eating the pecan pie.
=====Crisis on Earth-X=====
While in England 1183 A.D., Jax, Stein, Sara and Mick are dealing with soldiers, when Sara asks if they have RSVP'd for Barry and Iris's wedding, they deal with the soldiers and then leave for Central City. During rehearsal dinner, Jax found out from Stein that Cisco and Harry Wells came up with a cure to finally break up so that Jax can transform into Firestorm on his own, something Jax didn't take very well. Jax and the Legends stayed the night at Martin's house. Jax and the team attended the wedding, but was interrupted by a group of Nazis led by Dark Arrow, Overgirl, and Prometheus. Jax and Martin merged into Firestorm and helped fight the Nazis until they captured Prometheus.
Jax, Sara, and Stein come up with a theory of time-traveling Nazis, which could mean they are anachronisms, but it doesn't make sense as they ruined Barry and Iris's wedding. Jax, Harry, and Caitlin try to find a way to track down the Nazis, but it doesn't go so well as Cisco is out of commission. Stein arrives and asks to speak to Jax alone. Jax finally reveals why he's acting that way. Once Firestorm is disconnected and Martin leaves, Jax feels that he will no longer have what he really wants: Stein, calling him the closest thing he has to a father. The heroes discovered that Prometheus and the rest of the Nazis came from Earth-X. Jax and Martin teamed up to face the Nazis again, but were teleported with Oliver Queen, Barry, Sara, and Alex Danvers to Earth-X.
The heroes were held captive and encountered a prisoner named Ray Terrill. When they were to be killed by Quentin Lance from Earth-X, Leo Snart, Snart's Doppelgänger from Earth-1, who rescued them, and they saw that Ray also had powers. The heroes teamed up with the Freedom Fighters to try to convince Winn Schott to try to return home. Jax and Stein sorted things out and teamed up with the others to come up with a plan to infiltrate the Nazi base. Upon infiltrating, Jax and the team attacked the Nazis to cross the portal to Earth-1.
====Martin's death and leaving the Legends====
While fighting the Nazis on Earth-X, Stein was shot multiple times. Jax merged with Stein and Firestorm crossed with Oliver, Barry, Alex, and Sara, Ray and Leo in the portal to Earth-1. His psychic link to Jax kept him alive, but it caused Jax to suffer from Stein's own injuries and would eventually kill both. Despite Jax's protests, Stein made the executive decision to finally sever the link, dooming himself but saving Jax, allowing Stein to pass away in peace. 
Jax went with Clarissa and Lily to reveal with sadness and tears that Stein died. After the heroes managed to win the battle, Jax and all of Stein's friends attended his funeral, remembering his father figure and friend. Jax returned to the Waverider with the rest of the team and his new member, Leo.
After Martin's death, Jax tried to persuade Martin's younger self to try to avoid his fate, but the younger Martin decided that living his life differently to avoid that death would alter the life he'd lead in the future, possibly never meeting his friends and altering time to lead to his daughter's birth, and it wasn't worth it. No longer able to become Firestorm, and needing time to make peace with losing Martin, Jax took a leave of absence from the team.
====Becoming a father====
At some point after leaving the Legends, Jax got married. Around 2022/2023, he and his wife had a daughter, Martina, named after Martin.
====Fight against Mallus====
In 2023, Jax briefly returned to help the Legends battle Mallus' army and met his replacement, Wally West. Upon seeing the Legends conjure up a giant Beebo doll to defeat the demon, Jax mentioned how much he missed them. Jax revealed to the team his marriage and fatherhood before leaving once more, bidding farewell to his friends.
====Anti-Monitor Crisis====
During the Anti-Monitor Crisis, Jax as well as everyone in the multiverse except for the seven Paragons, was killed in an antimatter wave by the Anti-Monitor on December 10, 2019, only to be restored a month later, after the Paragons and the Spectre created a new universe.
===New multiverse===
Jax is still alive in the new multiverse. With the exception of Rip Hunter, no one knows the workings of the Waverider better than Jax.
====Becoming Captain Cold====
=====The Missing Necrians=====
In 2022, Jax and Alanna were visited by Kendra Saunders, Scythian Torvil and Alda Hall-Saunders, who had been called by Ray Palmer for an emergency. He greeted Ray and Nora Darhk with happiness to discover that the meeting was to save the Legends, which they accepted, and went with Mick Rory to take their time courier. However, upon learning that Mona Wu and Mick and Kayla's children were kidnapped, Jax and the former Legends agreed to save them. Jax was given the cold gun by Mick and he became the new Captain Cold. 
To honor Leonard Snart, Jax used his old goggles and jacket to travel with the former Legends to different time periods to chase down the Necrians in history, and find out where the children were, discovering that the kidnappers were Kamaya and Kyle, Kayla's parents. Jax, Ray, Kendra, Mick, and Scythian were reminiscing about their old friends and their old adventures until Kayla stepped in to say that Mona and the kids were in Necria. Captain Cold and the former Legends went to the planet to confront the Necrians, but learning that Kamaya and Kyle only wanted to see their grandchildren, the former Legends made peace, preventing an alien invasion. After returning to Earth, Jax was happily reunited with Alanna, and the former Legends took a selfie to send to Nate Heywood.
=== Potential future===
In a potential future in 2049, Jax went to a bar in Star City to meet with Ray, Sara Lance, Kendra, Mick, Scythian, and Wally West . As they chatted, Jax talked about how Martina became a scientist at S.T.A.R. Labs, surprising her friends, and they kept talking about her children until Jax, Sara, Mick, Ray, Kendra, and Scythian disappeared.
==Personality ==
<tabber>
|-|As a civilian=
Jax was a very hard worker, academically and athletically. Knowing his widowed mother couldn't afford college, he focused hard at school to get a 4.0 and was eventually rewarded with a football scholarship. He also cared about the well-being of other people. During the night of the particle accelerator explosion, he saw an injured person on the field and didn't even hesitate to help them to safety, which resulted in his knee being injured from the explosion. Following that, he entered a depression as all of his hard work had been for naught and he had to work as a mechanic for a living because he lost his only means to afford college.
|-|As Firestorm=
Jax eventually becomes happy again when he found his calling to help people by becoming Firestorm. He also displays a high amount of potential as Firestorm as Martin Stein quickly changed his opinion of him when he was chosen to be the next Firestorm. Given, his original opinion was when he knew nothing of Jax other than he was a high school graduate compared to a well-accomplished scientist who was the other candidate. Since joining the team, Jax has developed a crush on Kendra Saunders, though it has seemed to pass.
Despite Jax's good traits, he is arrogant and egotistical to the point of being immature, when these traits started to put the Legends mission to stop Vandal Savage in danger, Martin was then forced to tell him to grow up and not everything is about him. These traits have disappeared after this, especially after Martin was captured by Vandal.
In battle, Jax is willing to put all of his power to use and not restrain them. He is shown to be willing to kill in battle, such as using a gun to fight in the Old West, personally trying to deal a death blow on Chronos until he was revealed to be Mick Rory, and partaking in obliterating The Pilgrim. When Rip Hunter was turned into an ally of the Legion of Doom, Jax first tried to reason with him and then briefly berated him for turning on his team. It was after Rip snapped her neck that Jax was overwhelmed with enough fury to go after Rip and attempt to shoot him, though a revived Sara convinced him to not let his rage overcome his humanity.
Due to his background and ethnicity, Jax has always expected to deal with racism and bigotry. However, when going undercover at during the American Civil War, and getting to experience the kind of cruelty of slavery towards black people firsthand, Martin felt a surge of hatred, anger, and fear well up inside of Jax that he had never felt before, so much that through their psychic link, the sheer weight of Jax's emotions stunned him physically. Jax discovered a sense of pride in his culture and his roots when he saw the indomitable spirit of the people enslaved along with him. Suffice it to say, he felt a profound sense of satisfaction in seeing the slave owner's plantation and mansion consumed in the inferno he had started.
After learning of the message sent by Barry Allen from the year 2056 and that he altered the timeline, he did not criticize the present Barry for his actions, as he would have done exactly the same thing the latter did, if he was in an emotional state and not thinking clearly; as Jax is no hypocrite.
</tabber>
==Powers and abilities==
===Powers===
====Former powers====
*Firestorm Matrix connection/Meta-human physiology: When Jax merges with Martin Stein, the two create the nuclear-powered composite being Firestorm. The F.I.R.E.S.T.O.R.M. Matrix is controlled by two individuals, or "halves"; when they achieve physical contact, the Matrix takes over their biology and merges them into a singular being. When the two halves of Firestorm merge, the Matrix has them take on the form of the individual that has the stronger body. However, after Martin took the Firestorm Matrix cure that was created by Cisco Ramon and Harry Wells, it severed Jax and Martin's link; therefore he no longer has any connection to the Firestorm Matrix. 
** : Firestorm has so far seen to have at least two methods to achieve flight. The first and most common is when he uses fires nuclear blasts downward at a consistent rate, thereby generating enough force to defy gravity and allow for stable prolusion and gliding. This flight style is his preferred and most practiced choice. The second method is unclear, as he is shown to be able to fly at impressive speeds without the need of his blasts. How he achieved this skill or how he even does it is unclear.
**: While fighting Nazis in 1944, Jax and Martin discovered that their nuclear powers can manipulate matter at an atomic level and arrange its subatomic structure into a different substance altogether. He first used this by turning a rifle into dust by grabbing it. Using this ability, Firestorm is able to transform a radioactive meteorite into water. Over time, the duo further refined this skill, able to transmute machinery into countless smaller and more complex compounds, such as a shielded safe into a pile of jellybeans.
**: Firestorm is virtually a living reactor, and as such, creates great amounts of nuclear energy via the innumerous atomic reactions constantly occurring in his body. That and his mental capacity to process both fission and fusion, allow him to harness the energy emitting from his either his own body or any near source of energy that's near.
**: Firestorm has shown the ability to not only generate nuclear power but also contain the energy coming from outside sources by absorbing its output. He did so when he absorbed the blast from Vandal Savage's nuclear warhead. He's also able to manipulate and absorb the flow of other forms of energy, as shown when he was able to siphon off energy from the Pentagon.
**Psychic link: Jax can hear Martin's disembodied voice while the two of them are merged into Firestorm. Even when they are separated, their link allows them limited communication of sensations or emotions.
**: Due to the nuclear nature of the transmutation of the two bodies, Firestorm is able to release nuclear energy from parts of his body in the form of fire. He can use his control over the energy to project it willingly in the form of concussive blasts. These "nuclear blasts" are often shown to be quite powerful and have shown to be able to range from being able to knock unarmed humans out unconscious to being hot enough to burn through solid structures and even causing extreme harm to meta-humans. The impact of these blasts can sometimes create an explosive-like force.
** : While in his Firestorm form, Jax has performed feats of strength that surpass those of normal humans. He was able to rip apart straps made of Tiberian steel, which were able to encase both Hawkman and Hawkgirl.
===Abilities===
* Peak of human physical condition: Jax is gifted with great natural talent in athletics. During his time in high school, he was a star quarterback who earned a full scholarship to any college/university of his choosing. However, after the particle accelerator explosion, his leg was too damaged to ever play football again, costing him his scholarship. He was fast enough to run across the 360 foot-long Koshmar grounds in under 12 seconds (over 20.45 miles per hour), even with his torn ACL.
*High-level intellect: Whilst he lacks a college degree, Jax is highly intelligent, having quickly learned how to operate and perform maintenance on the future technology of the Waverider. He is also shown to be a talented actor, able to perform an accurate British accent. 
**Expert mechanic/engineer: To help his mother with bills, Jax gained a job in a car repair. To which, his skill at have prevented very adaptive, able to apply it to the various needs of the Waverider and technology encountered on their travels. He eventually was appointed by Rip to be chief engineer for the Waverider (though Mick Rory regularly reminds him that he's the only engineer on board). Jax's intellect from his time traveling adventures has risen to a point where he finds himself bored with 21st century engineering.
*Skilled hand-to-hand combatant: While unknown to what degree, Jax has shown some skill at hand-to-hand combat, being able to fight off and even tackle a member of Vandal Savage's cult while the Legends attempted to reclaim Carter Hall's body. This is probably due to his past experience as a quarterback. He is also shown to have a very effective punch, able to knock out a League of Assassins member with a single strike and hold off a 12th-century knight wielding a sword with a bow. Jax was even later able to disarm and knock out Malcolm Merlyn after stabbing him with an arrow.
**Skilled marksman: In the Old West, Jax used a revolver to shoot a gun out of a man's hand while on a horse. He also wielded a bow in the 12th century and fired two arrows in the chests of two knights on horses.
===Weaknesses=== 
*Torn ACL: Due to being hit by dark matter rather hard and subsequently slamming into a wall, Jax's ACL (anterior cruciate ligament) was badly damaged and as a result, he cannot run too hard on it. This is evidenced when Jax ran across the Koshmar prison courtyard to get to a power switch, only to barely make it due to his knee cramping.
====Former weaknesses==== 
*Psychic link: Although the psychic link allows Jax and Martin limited communication of sensations or emotions when they are not in their Firestorm form, it also has another drawback, if one of them dies the other will die as well, this was evidenced by the fact when Martin was mortally shot, he only surviving because of the psychic link he had with Jax. Unfortunately, it was slowly killing the latter, however, after Martin took the Firestorm Matrix cure that was created by Cisco Ramon, Caitlin Snow, and Harry Wells, it severed his and Jax's link, thus; saving Jax's life.
==Equipment==
===Original multiverse===
====Former equipment==== 
*Firestorm suit: Sometime after leaving Team Flash and before joining the Legends, a suit was made for Firestorm. Only Jefferson can wear it, as he is the host of Firestorm. It only appears whenever Jax and Martin merge, and seems to be based around the quantum splicer that Eobard Thawne and Cisco Ramon developed.
*Speed Force rifle: Designed by Eobard Thawne to temporarily incapacitate a speedster, this weapon has become Jax's personal sidearm when he is not able to become Firestorm.
===New multiverse===
*Cold gun: Jax was given the cold gun by Mick Rory.
*Captain Cold's jacket: Jax was also given the Leonard Snart's jacket by Mick Rory.
*Goggles: Jax also wears a pair of blue wraparound goggles, which are designed to protect his eyes from the flashes given off by his Cold Gun.
====Former equipment==== 
*Firestorm suit: Sometime before joining the Legends, a suit was made for Firestorm. It seems to be based around the quantum splicer that Eobard Thawne and Cisco Ramon developed.
==Appearances==
===The Flash===
====Season 2====
*
====Season 3====
*
====Season 4==== 
*
===DC's Legends of Tomorrow===
===Vixen===
====Season 2==== 
*
===Arrow===
====Season 5==== 
*
====Season 6==== 
* 
==== Season 8==== 
*
===Supergirl ===
====Season 3==== 
* 
===Comics===
====EARTH-PRIME ====
*
===The Chronicles of Cisco===
*
==Gallery==
===Era-specific attire===
Jefferson Jackson and Martin Stein in Tintangel, England 821 attire.png|Jefferson Jackson and Martin Stein in 821
Jefferson Jackson in France 1637 attire.png|Jefferson Jackson in 1637
Jefferson Jackson in 1863 attire.png|Jeferson Jackson in 1863
Jefferson Jackson in 1874 Wild West attire.png|Jefferson Jackson in 1874
Jefferson Jackson in 1942 attire.png|Jefferson Jackson in 1942
Jefferson Jackson in 1988 attire.png|Jefferson Jackson in 1988 attire
===Promotional images ===
====DC's Legends of Tomorrow ====
===Concept art===
Firestorm concept art.png|Firestorm
=====Season 1 =====
Firestorm DC's Legends of Tomorrow promo.png|Jefferson "Jax" Jackson as "Firestorm"
==Trivia== 
*Apparently, Firestorm doesn't exist on Earth-38, implying that if Jefferson has a doppelgänger on that Earth, he never became Firestorm.
*Jax must merge with Martin Stein weekly, to stabilize him. 
**Oddly, Jax shows no similar symptoms as Stein; this suggests the nuclear power is solely held by Stein and Jax is simply the stabilizer.
*A chronic problem for Jax while traveling with the Legends is that he faces racial prejudice in years before the late 1900s.
*Jax calls Stein "Grey" due to his age and the color of his hair. Stein initially was irritated by this nickname, but came to accept it. 
**When Stein was Captain, he said his name was "Captain Grey".
* Jax has quit college as of 2017, as he found it ridiculous to learn how to become an engineer when he already had the knowledge and skills for the job after spending two years performing maintenance on the Waverider. 
*He loves the movie Police Academy.
*Jax has expressed an attraction towards Kendra Saunders/Hawkgirl, Courtney/Stargirl, and Zari Tomaz.
*Jax considered Martin as a surrogate father as he never knew his biological father. Likewise, Martin viewed Jax as a surrogate son. This was expressed greatly right before Martin died in the battle against Earth-X. Jax also shared this familial bond with Clarissa and Lily, who considered him a son and brother respectively, telling Jax that he is a part of their family at Martin's funeral. 
**Similar to how Stein's grandson was named after Jax's predecessor, Ronnie Raymond, Jax named his daughter Martina after Stein.
*With Martin Stein, Ronnie Raymond, and Valentina Vostok all deceased, Jax is the only surviving component of the meta-human, Firestorm.
*Jax used to do drugs but quit as revealed by Martin Stein.
==Behind the scenes== 
*In the DC comics, Jefferson Jackson is a former student of Bradley High School in Manhattan, New York. During his tenure at Bradley High, Jackson became a member of the school's championship basketball team, where he met fellow student Ronnie Raymond. The two became close friends, and Jackson frequently aided Raymond during the numerous episodes wherein the latter would find himself embroiled in conflicts with his rival Cliff Carmichael. Jackson dated a young woman named Stella, and the two frequently double-dated with Raymond and his girlfriend, Doreen Day.
*Jax's background borrows elements from the New 52 origin stories of both Ronnie Raymond and Victor Stone aka Cyborg, all of them being former high school quarterbacks with promising futures, before an accident occurs that ends that dream and instead leads them into the life of a superhero.
*Jax replaced Ronnie Raymond because Robbie Amell, Ronnie's actor, was unable to commit as a series regular for ."Robbie Amell On Why He Was Killed Off On The Flash And The Real Explanation Behind The X-Files Finale" - Bleeding Cool
==References==
es:Jefferson Jackson
fr:Jefferson "Jax" Jackson
it:Jefferson Jackson
pl:Jefferson Jackson
Category:Vigilantes
Category:Allusions to the comics
Category:Legends members
Category:Time travelers
Category:Time aberrations
Category:Characters with Thanagarian mutations
Category:Breachers
Category:Manhawks
Category:Characters with psychic powers
Category:Needs Power link