Battle of Odessen The Battle of Odessen occurred around 3631 BBY when Emperor Arcann of the Eternal Empire , having learned the location of the Alliance base on the planet Odessen from SCORPIO , who took over his Eternal Throne , led the detachment of the Eternal Fleet still under his control to destroy the Alliance . SCORPIO , who was manipulating her enemies to destroy each other , informed the Alliance about the imminent threat , giving them enough time to face the Eternal Fleet in the " Gravestone " . Lana Beniko determined that the only way to ensure safety of the Alliance was to annihilate Arcann ' s Eternal Flagship and along with Senya Tirall accompanied the Alliance Commander in the infiltration of the flagship . Senya separated from the others to find Vaylin , while Lana and the Commander made their way to confront Arcann on the bridge . Lana then was informed by Theron Shan that the rest of the Eternal Fleet had turned on Arcann as well , targeting the Arcann ' s flagship to eliminate both him and the Commander in one fell swoop , which Lana recognized as SCORPIO ' s true plan from the start . Reaching the bridge , Beniko stayed behind to deal with a squad of Knights of Zakuul , leaving the Commander to confront Arcann alone . The Commander defeated Arcann and crushed him under a pile of rubble , and as the flagship was coming apart , Beniko and her team commandeered a Zakuulan shuttle while the Commander narrowly escaped in a Zakuulan starfighter . On their way back to the " Gravestone " , Senya contacted them and revealed that she was alive and so was Arcann , whom she was taking away in the hopes of redeeming , before she escaped into hyperspace aboard Arcann ' s personal shuttle . With little time to worry about Senya , Theron Shan fired the omnicannon on the Eternal Flagship , creating a massive explosion that wiped out the present portion of the Eternal Fleet . The Battle of Odessen had become the rallying point the Alliance needed for all the forces seeking to oppose the Eternal Empire , swelling their ranks and giving them the capability to repel future invasions Prelude . During the Alliance attempt to take over the Eternal Fleet through the use of GEMINI Prime , SCORPIO betrayed the Alliance and through the GEMINI frequency took control of the Eternal Throne herself . She then deliberately left a significant detachment of the Eternal Fleet seemingly under Emperor Arcann ' s control and manipulated her enemies to destroy each other . She provided Arcann with the location of the Alliance base on Odessen , correctly predicting that Arcann would deal with the Alliance and its Commander first instead of her , and also warned the Alliance about Arcann ' s imminent arrival , giving them a head - start . The Alliance base and the surrounding area were protected from aerial bombardment by a planetary shield , ensuring that the Eternal Fleet could not wipe the Alliance out with a single devastating attack , but that still left the base vulnerable to walkers and troops . Aric Jorgan volunteered to remain in the base in case of a ground invasion , and Kaliyo Djannis elected to join him , though the Commander assigned one other Alliance member to watch over the two . As Arcann ' s Eternal Fleet led by his Eternal Flagship jumped in - system , the Alliance leadership boarded the " Gravestone " to meet them in orbit . The battle . The Eternal Fleet opened fire , which the " Gravestone " deflector shields absorbed , and Koth Vortena ordered his crew to man the battlestations . Theron Shan went down to the omnicannon , using it to fire the on the Eternal Fleet . Lana Beniko came to conclusion that the only way to ensure Odessen ' s safety was to destroy Arcann ' s Eternal Flagship , and decided to board it along with the Commander , Senya Tirall and two more Alliance members , tasked with disabling the flagship ' s weapons and shields . Theron fired the omnicannon at the Eternal Fleet warship blocking the direct path to the flagship , which also knocked out the flagship ' s shields long enough to allow the Alliance shuttle to land in its hangar . Upon disembarking , the Alliance forces were attacked by scores of skytrooper s , which they managed to fend off . Sending two teams to disable the shields and guns , Lana and Senya and the Commander proceeded to infiltrate the flagship . At this point , the " Gravestone " omnicannon stopped working for no discernible reason and Koth send his best engineer Tora to assist Theron . SCORPIO then revealed herself to be behind the malfunction and attempted to remotely take over the " Gravestone " , but Vortena stopped her by locking the droid out of the ship ' s systems . After spotting her mother on the security cameras , High Justice Vaylin contacted the group and revealed that Emperor Arcann was on the flagship ' s bridge , which prompted Senya to separate from the rest and confront her daughter personally . The Commander and Lana fought their way through skytroopers and Knights of Zakuul , defeating the Exarch Shernisa Varless and coming across an experimental assault skytrooper KJ - 931 . Koth placed a well - aimed shot on the flagship that hit the droid and allowed Lana and the Commander to gain the upper hand , while the teams send to disable shields and guns likewise accomplished their tasks with relative ease . The Commander and Lana proceeded towards the bridge , defeating the Knight Commander Dara Nadal , at which point Theron noticed and informed Lana that the Eternal Fleet was now targeting the Eternal Flagship , which Lana recognized a part of SCORPIO ' s ploy to eliminate both Arcann and the Commander in one fell swoop . The two of them then reached the bridge , but were pursued by four Zakuulan Knights , which Lana stayed behind to deal with , leader the Commander to confront Arcann alone . The two of them alone on the bridge , Arcann explained to the Commander that his animosity was never directed against them personally , but rather against his father Valkorion , whose spirit not existed within the Commander ' s mind . Demanding Valkorion to address him , Arcann restrained the Commander with the Force and eventually struck them with his lightsaber , an attack that was unconsciously blocked by the Commander due to Valkorion ' s presence . The two then engaged in a lengthy duel , with Arcann conjuring Force manifestations to assist him , while the Commander picked up a discarded Knight - Captain ' s shield to block Arcann ' s attacks . Eventually the Commander managed to overpower Arcann and had him at their mercy , but at this point Eternal Fleet warships opened fire on the flagship , causing multiple fires and serious damage throughout , and crushing Arcann under a pile of falling debris , while the Commander had to retreat to avoid the same fate . Learning from Theron that the omnicannon was back online and from Lana that the rest of their infiltration team sans Senya was already at their escape shuttle , the Commander took Lana ' s suggestion to board a small patrol craft nearby rather than run all the way back to the shuttle as the ship was falling apart . Meanwhile Senya reached the bridge and used telekinesis to clear the debris and pull her son from under it , wounded from the fight and with his cybernetics damaged . Vaylin then returned to the burning bridge , mocking her mother for being too late to save Arcann and calling her weak for leaving her children behind . Senya offered both her children to come back to her , but Vaylin angrily refused and launched herself at her mother , only for Arcann to Force - push her away . Enraged at her brother , Vaylin demanded to know why he saved Senya ' s life , but before he could answer , falling debris forced Vaylin to retreat and flee back to Zakuul , while Senya took her wounded son to his personal shuttle . Commandeering a small Zakuulan craft , the Commander escaped the burning flagship and contacted the Alliance for status updates , at which point Senya revealed that she was alive and taking Arcann away in hopes of redeeming him . Koth Vortena pleaded the Commander to shoot her shuttle down , but the Commander relented , allowing Senya and Arcann to escape . Theron Shan then fired one last omnicannon shot on the Eternal Flagship , creating a massive chain explosion that completely wiped out the present portion of the Eternal Fleet , winning the battle for the Alliance , who did not suffer a single casualty . Aftermath . Back on Odessen , Lana congratulated the Commander on their victory , while Kaliyo and Jorgan confirmed that no ground forces ever attempted to land . Arcann was effectively dethroned and following the victory , Imperial and Republic forces have come pouring in to join the Alliance ' s cause , bringing with them enough starships to form the Alliance fleet . Although Odessen ' s location was no longer secret , its defenses were formidable enough to ensure the Alliance ' s safety even against the Eternal Fleet . Apart from Arcann , who was taken by Senya to unknown location , the only other survivor from Zakuulan forces was the High Justice Vaylin , who returned to Zakuul only to find SCORPIO in control of the Eternal Throne . Vaylin cut through SCORPIO ' s skytrooper defenses , but to her surprise SCORPIO welcomed Vaylin and explained she only took the throne to grant free will to the Fleet ' s GEMINI captains . Some of the GEMINIs used their newfound freedom to explore the galaxy , taking their warships away from Zakuul , but many decided to stay with SCORPIO , whom they now revered as " Great Mother " . Her mission accomplished , SCORPIO willingly surrendered the Eternal Throne to Vaylin , offering to stay and advise the new Empress of Zakuul on how to destroy their enemies . Behind the Scene . Early on in Chapter XVI : The Battle of Odessen , player has to assign roles for Vette , Gault Rennow and Torian Cadera , ordering one to stay behind on Odessen , another to sabotage the weapons on the Eternal Flagship , and the third to sabotage the flagship ' s shields . In any case , shields and guns are disabled successfully and the ground forces never land on Odessen , the only difference being in dialogue . On the flagship , the player must choose to receive assistance from either Zakuulan weapons and armor or defensive turrets ; this choice only affects the gameplay and has no effect on the story . During the duel against Arcann the player can use a special weapon constructed during Chapter XII : Visions in the Dark to receive two additional special abilities ; this is not reflected in dialogue and is not required to defeat Arcann . The player can take a Dark Side option named [ Kill Arcann ] at the end of the duel , but Arcann will survive and be crushed by debris regardless . At the end of the battle the player must either make a Light Side option to let Senya and Arcann go , or a Dark Side choice to open fire on their shuttle . Although they will escape into hyperspace regardless , the choice only affecting some lines in the " " , dialogue remaining in the game files indicates that at some point the second option actually led to the shuttle being shot down and burning in Odessen ' s atmosphere , with both Senya and Arcann dead . Arcann ' s fate remains the same in the finished version , though other events surrounding the battle may change depending on previous Dark Side choices made by player . Either Kaliyo or Jorgan can be killed or permanently exiled at the end of Chapter XIII : Profit and Plunder , in which case different reason will be given for requiring someone else to stay alongside the remaining person . The biggest possible difference involves Koth Vortena and his crewmembers Len Parvek and Ralo , who can quit and abandon the Alliance depending on the player ' s choices during Chapter X : Anarchy in Paradise . In this case , Tora become the captain of the " Gravestone " instead , though she will still leave the bridge to help Theron Shan with the omnicannon during the battle . Koth will use this opportunity to sneak his way onboard the ship along with his crew and pretend to have forgiven the player , stopping SCORPIO from taking over the " Gravestone " and firing on the Eternal Flagship to hit KJ - 931 , claiming that stopping Arcann is all that really matters . However , after Arcann is finished , Koth will reveal that it was just a ploy to steal the " Gravestone " , as he is worried the player would use it to destroy Zakuul . Putting Theron and Tora in stun cuffs , Vortena ejects them in an escape pod , after which he hijacks the " Gravestone " and takes it into hyperspace , robbing the Alliance of its best weapon against the Eternal Fleet .