Fatal Terror

Season 6 episode 13 of Nightwing & Batgirl.
The episode starts at 31st Century. The Legion of Superheroes (comprised of Brainiac 5, Lightning Lad, Saturn Girl, Ferro Lad, Shadow Lass, Bouncing Boy, Chameleon Boy, Matter-Eater Lad, Colossal Boy, Cosmic Boy, Dream Girl, and Triplicate Girl) had a fierce battle against the Fatal Five (comprised of Validus, Mano, Emerald Empress, Tharok, and Persuader), which later saw the villains defeated. Their latest scheme has been thwarted. 
The scene moves 1 month later after the Fatal Five's defeat. They have returned and declared war against the Fatal Five once again. They made a surprise attack at the Legion of Superheroes' headquarters. This time, they were able to defeat the heroes and settle the score. 
"Now that we are able to take down these young heroes that stand in our way, we shall move on with our plan. We shall get back to the past to achieve our long overdue vengeance and eliminate the Justice League once and for all!", Validus said.
"It's about time.", Emerald Empress said.
"No! You shall not use the time bubble!", Braniac 5 told them, but he was down and there's nothing he can do.
"Wait! You can't do that! You'll change history.", Bouncing Boy warned them.
"You'll disrupt the space-time continuum.", Ferro-Lad added.
But the Fatal Five still proceeded. The Emerald Eye had left the Legion of Superheroes temporarily immobilized. 
"There's nothing you can do now, Legion!", Mano told them.
"We are ought to conquer each and every one of the universes!", Validus added.
"No!", Saturn Girl exclaimed.
The Fatal Five now proceeded to enter the time bubble and now time traveled to present day Earth. They began their search for the Justice League.
The scene moves to Gotham. Nightwing, Batgirl, and Plastic Man battled Kite-Man and his kite-gliding henchmen in their usual crime spree. Nightwing and Batgirl used the R-Plane and fired lasers at their gliders. When their gliders are destroyed, Kite-Man and his henchmen used parachutes to land back down safely. When they landed, Plastic Man used his elasticity powers to take all of them down. They thwarted his attempt to steal a vintage aircraft. Later, policemen came and arrested Kite-Man and his henchmen. Nightwing and Batgirl thanked Plastic Man for the team up.
Back at 31st Century Earth, home to the Legion of Superheroes, they were now snapped out from immobilization as the Fatal Five had now escaped and accomplished their plan of traveling to New Earth, the Nightwing & Batgirl timeline. At the Legion of Superheroes headquarters, the heroes can't believe they failed.
"No way. They did it.", Lightning Lad said.
"And we don't know what happens next.", Brainiac 5 added.
"They might be out to destroy the universe.", Saturn Girl added.
"What are we gonna do now?", Shadow Lass asked. 
"Some of us gotta go and follow them.", Brainiac 5 answered.
"Yeah. Right.", Bouncing Boy agreed.
"But who?", Matter-Eater Lad asked.
"Hmm. Let me think. Maybe you, you, you, you, and I.", Brainiac 5 told them, as he pointed out at Ferro-Lad, Lightning Lad, Saturn Girl, and Shadow Lass.
"While all the others who'll be left here, I got an important job for you.", Brainiac 5 told the others.
"Guard the Time Bubble from any possible intruders?", Bouncing Boy asked.
"Exactly.", Brainiac 5 replied.
"We can handle this.", Colossal Boy said.
"Alright, Bouncing Boy. It's up to you to maneuver the Time Bubble and set it to New Earth, home to the Justice League.", Brainiac 5 told him.
"Yes, Brainy. I shall send you directly there.", Bouncing Boy said, as he set up the Time Bubble.
"Thanks.", Brainiac 5 replied.
"Wait. Since you'll be traveling to the past, that means we will have no communication for the duration of your stay at New Earth, right?", Triplicate Girl asked.
"Unfortunately, yes.", Brainiac answered. "That's why I'm counting on you, to protect the time bubble and our headquarters from any possible intruders.", he told the other Legionnaires.
"You can count on us.", Triplicate Girl said.
"Thank you very much.", Brainiac 5 replied.
Now, Bouncing Boy turned activated the Time Bubble, and the 5 Legionnaires are now sent to New Earth. 
"Now, where are the Fatal Five?", Lightning Lad asked. 
They saw a sign which said "Gotham City". 
They saw a crime happening. It was Polka-Dot Man, Ten-Eyed Man, Condiment King, Cavalier, and Sweet Tooth, causing destruction at a peaceful market. Ferro-Lad almost sprung into action if not for Brainiac 5's intervention. 
"As much as possible, let's avoid interaction with anyone here. Anything we do might disrupt the space-time continuum.", Brainiac 5 warned his teammates.
"So what now? Are we supposed to just stand here and do nothing?", Saturn Girl asked.
"I'm sure this city has its protectors.", Brainiac 5 replied.
"Then what's taking them so long?", Ferro Lad asked.
Later, a car came streaking and stopped right beside them. From the car came down Nightwing and Batgirl.
"That's why.", Brainiac replied.
"Oh, they can't fly.", Lightning Lad asked.
"Ah. 21st Century.", Ferro Lad said.
Nightwing and Batgirl took down the criminals easily. After that, police came to pick up the villains.
Later, Brainiac 5 called Nightwing and Batgirl.
"Hey. So who are you guys?", Nightwing asked.
"Well, we are the Legion of Superheroes.", Brainiac 5 said.
"Let us guess, you're from the future, right?", Batgirl asked.
"Yes we are.", Shadow Lass answered.
"That's so cool!", Batgirl said. "But how did you find your way here anyway?", she asked them.
"Well, it's because our archenemies attacked our headquarters and used our Time Bubble to travel back in time. They're out to take revenge on the Justice League.", Lightning Lad explained.
"My goodness. How many are they?", Nightwing asked.
"Five.", Ferro Lad answered.
"Five? And they expect to take on a whole League?", Nightwing asked, as he laughed.
"Well, you know, they're not to be underestimated. We're from the future remember. And we don't yet, they may have other plans to your universe besides their personal vendetta against the Justice League.", Brainiac told him and Batgirl.
"Now, that's trouble.", Nightwing said.
"Let's better take this mission seriously.", Lightning Lad told Nightwing.
"Do I look like I'm not?", Nightwing asked.
"Cut it out.", Batgirl told Nightwing. 
Meanwhile, the Fatal Five are at Metropolis.
"Ugh! It would take us weeks scouring this entire planet in search of the Justice League!", Persuader said, losing his patience.
"I have a more convenient idea.", Emerald Empress told him.
She used her powers to take control of communication lines at Metropolis. Now, the Fatal Five's faces are seen on every monitor, phones, and television screens throughout the city. Now, the Fatal Five broadcasted their message.
Meanwhile, Batgirl sent a distress signal to Martian Manhunter, telling them they got something urgent to tell and its concerning a group of superheroes from the future. Martian Manhunter teleported them and the Legion heroes to the Watchtower right away.
Back at Metropolis, the Fatal Five are now relaying their message.
"Greetings, Justice League. We would like you to come out from any shell you are hiding as soon as possible. We are out to destroy every alternate Earths we come across. Starting with your precious planet.", Tharok said.
"If you value your precious planet pretty much, then show yourselves and surrender to us.", Emerald Empress added.
Meanwhile, Superboy and Supergirl took notice. 
"What the...", Superboy said.
"We gotta tell the Justice League about this quick!", Supergirl said.
Later, Emerald Empress stopped the broadcast. They saw the people of Metropolis visibly terrified.
"That shall do it. It would catch their attention soon enough.", Emerald Empress said.
Meanwhile at the Watchtower, the Legion of Superheroes are about to explain their concern regarding Fatal Five, when the Fatal Five showed on one of their monitor screens. The League are able to receive the Fatal Five's message. Superboy and Supergirl, through their communicators, also warned the Justice League about them.
"What do we do now?", Flash asked.
"They left us with no choice.", Superman said.
"They're bluffing.", Batman said.
"I guess we got to surrender.", Wonder Woman said.
"And become their captives? There's no way in hell I'd be part of that.", Batman replied.
"Why don't we settle this in a way that we'll all understand?", Brainiac 5 proposed.
"We fight?", Nightwing asked.
"Hell yeah.", Lightning Lad said.
"Much better.", Batman said.
"The Fatal Five are clever. They knew we've drawn our inspiration from you guys. That's why they seeked to destroy you. And by exterminating you for good, that would also mean we wouldn't exist, and we'll also be wiped out from the space-time continuum, giving them full-fledged victory. If we get wiped out from existence, who's gonna stop them from conquering the multiverse?", Brainiac 5 explained.
"Fighting them would put Earth into much greater risk.", Wonder Woman said.
"This is war. There are always risks.", Batman replied.
"If we lose, the fate of Earth would fall to the wrong hands.", Flash said.
"It's better to at least put up a fight than to surrender.", Batgirl replied.
"Then our plan is not to lose.", Ferro Lad said.
"Majority is in favor of fighting. We shall now send you out there to battle the Fatal Five.", Martian Manhunter said.
"Let's go.", Shadow Lass said.
Now, Nightwing, Batgirl, Superman, Batman, Wonder Woman, Flash, John Stewart and the five Legionnaires are sent to Metropolis. They finally faced off with the Fatal Five.
"Justice League. At last we meet!", Mano said.
"Honestly, we expected a whole armada of superheroes to come at us.", Tharok added.
"All we need is us.", Brainiac 5 replied.
"We don't need our full force to kick your asses", Nightwing said.
"Then prove it.", Persuader challenged.
Now, the conflicting sides clashed. Superman and Lightning Lad took on Validus, Nightwing and Ferro Lad took on Mano, Flash and John Stewart took on Persuader, Batman and Brainiac 5 took on Tharok, and Wonder Woman, Saturn Girl, and Shadow Lass took on Emerald Empress. Later, Superboy and Supergirl crashed the party and helped Superman battle Validus.
"Took you long enough.", Superman told his sidekicks.
"Better late than never", Supergirl replied.
However, Validus grabs both Superboy and Supergirl by their necks, slammed them on the ground and threw her away. Lightning Lad knocks Validus off using his powers, but was later overcame by Validus and he was knocked down unconscious. Nightwing was able to evade all of Mano's attacks and his touch, while Ferro Lad countered his attacks using his ferrokinetic abilities. Mano was defeated. Flash was too quick to be hit by Persuader's atomic axe, while John Stewart's constructs are durable. Later, John Stewart's power ring and Flash's quick strikes are able to overpower Persuader. However, Tharok defeats both Brainiac 5 and Batman, while Emerald Empress singlehandedly knocks down Wonder Woman, Saturn Girl, and Shadow Lass. 
"Time is running out, Empress.", Tharok told Emerald Empress.
"I know.", Emerald Empress replied, as she struck down Superman with her Emerald Eye of Ekron.
Now, she got the job done and knocked down the remaining heroes with her powers.
"We did it. We've taken them down!", Validus celebrated.
"Now, it's time for us to claim our ultimate prize.", Tharok said.
He now brought out and showed his Sun-Eater ball to his allies. He threw the ball to the ground and the Sun-Eater grew large.
"It's beautiful.", Persuader remarked.
"Now, let's ride.", Tharok told the others.
"I got some baggage of my own.", Emerald Empress said, as she lifted the unconscious beaten heroes using her emerald dome constructs. 
Now, they flew to outer space. Later, Emerald Empress left them hanging and floating in space, as she and her allies headed towards the sun. Now, Tharok activated the Sun-Eater. Later, the Leaguers from the Watchtower took notice of the floating bodies of the heroes in outer space.
Now, Captain Atom, Dr. Light, Hal Jordan, Martian Manhunter, Rocket Red, Steel, S.T.R.I.P.E., and Blue Beetle rescued the unconscious heroes. They were brought to Watchtower. Later, Mr. Terrific alerted everyone of a foreign object approaching the sun. Later, the fallen heroes regained consciousness.
The Legionnaires immediately looked at the tower's monitors and they were all surprised and terrified. They know what's approaching the sun.
"What is that thing?", Batgirl asked.
"No way!", Shadow Lass said.
"It's... the Sun-Eater!", Ferro Lad said.
"It is a weapon of mass destruction that feeds off stars and destroys solar systems. If it is able to completely devour the sun, we will all be wiped out!", Brainiac 5 said.
"How do we stop it?", Superman asked.
"The only thing that could stop it is a solar transducer. It's the only device capable of destroying the Sun-Eater's core.", Brainiac 5 answered. "The only thing is, its creation will take a huge amount of time.", he said.
"Then let's start building it.", Mr. Terrific said.
"You won't have to worry about time.", Flash told him.
"While we're at it, we might use everyone else's help slowing down the Sun-Eater.", Brainiac 5 suggested.
"We're on it.", Superman responded. 
Now, he called other Leaguers, namely Superboy, Supergirl, Hawkgirl, Hawkman, Shazam, Booster Gold, Blue Beetle, Fire, Ice, Firestorm, Captain Atom, Dr. Light, and Stargirl, to come with him in space to slow down the Sun-Eater. 
Meanwhile, the Justice League's most brilliant minds gathered.
"It's not easy to build a solar transducer. It requires a great number of rare elements", Brainiac 5 told them.
"And what exactly are these elements?", Nightwing asked.
"Quantum particles, dalamite crystals, quantum ore, anti-matter, and a stabilizer core.", Brainiac 5 enumerated.
"Luckily, I have some of those in my lab.", Ray Palmer/The Atom said.
"Sweet!", Lightning Lad said.
"Now, let's start!", Ferro Lad said.
Nightwing, Batgirl, Batman, Flash, Mr. Terrific, The Atom, and the 5 Legionnaires now worked together to build the solar transducer.
"Honestly, I underestimated your generation.", Brainiac 5 said. "Never thought you were already so advanced back then."
"This is the result of brilliant minds working together.", The Atom said.
Meanwhile at the Legion of Superheroes headquarters, they were under attacked by an unexpected foe. It is Terra-Man. He revealed that he is paid by the Fatal Five to keep the Legion of Superheroes in check. The Legionnaires left in the headquarters battled Terra-Man and his army.
Back at present day, Superman and the other Leaguers tried their hardest to slow down the Sun-Eater, while evading the Fatal Five's attack. 
"Struggling is of no use for you right now.", Tharok told them.
"Right now you are just wasting energy.", Mano added.
"The Sun-Eater is now nearing critical mass. And nothing you can do will be able to stop it from devouring your precious sun.", Emerald Empress continued.
"We won't stop! As long as we're still here, there is hope.", Superman said, as he struggles to lift up the Sun-Eater to avoid it from reaching the sun.
The heroes in the Watchtower rushed the creation of the Solar Transducer. Now, the five Legionnaires went out the Watchtower to keep the Transducer in check while it is about to be launched by the Watchtower's cannon. However, Brainiac 5 noticed one major slip up-a faulty conductor. He told the Leaguers but Ferro Lad told them to continue launch anyway. 
"But the transducer might fail!", Brainiac 5 told Ferro Lad.
"Trust me. I have a better idea.", Ferro Lad replied.
"What is it?", Shadow Lass asked.
"I'll be the conductor.", Ferro Lad answered.
"What? No! It's too risky!", Brainiac 5 said.
"It's a risk. But someone had to take it. In this case, it had to be me.", Ferro Lad said.
"Ferro! Don't!", Shadow Lass asked.
"Trust me. This will work. In the end, you'll thank me.", Ferro Lad said.
Now, Mr. Terrific counted to 3 and launched the transducer into space. Lightning Lad comforted Saturn Girl, while Brainiac 5 comforted Shadow Lass, as they embraced.
Ferro Lad hung on the transducer as launched to space. The Fatal Five are delighted at the sight of the Sun-Eater on the verge of devouring the sun. Superman saw the transducer coming and told his companion Leaguers to move out of the way. Everyone started to feel dense. They started to feel being wiped out of existence. The people on Earth feel it. Even the Legionnaires of 31st Century feel their existence wiped out as well. The Fatal Five were by Emerald Empress' emerald dome. Later, they are shocked to see what seems like a missile approaching the Sun-Eater. The Leaguers all headed back to the Watchtower.
"What, is that thing?", Mano asked.
"No way. It's a Solar Transducer!", Tharok said.
"And who's that boy riding it?", Validus asked.
"No way. It's Ferro Lad!", Emerald Empress recognized.
"End of the road, Fatal Five!", said Ferro Lad.
"He acted as the conductor! He'll blow up the whole Sun-Eater.", Tharok exclaimed.
He now proceeded to detonate the Transducer and hit the Sun-Eater's core, completely destroying the Sun-Eater. A huge explosion occurred. Ferro Lad died upon the impact and explosion. Once again, Emerald Empress protects her crew with her emerald dome, but the explosion reached them, knocking them unconscious. Superman, Hal Jordan, and the other Legionnaires later captured them and brought them back to the Watchtower. Shadow Lass carried Ferro Lad's unconscious body while tears fell from her eyes.
"He died a hero.", Saturn Girl said.
"He sacrificed for all of us.", Brainiac 5 said.
"He was my hero.", Shadow Lass added.
The Legionnaires and Leaguers all mourned the death and sacrifice of Ferro Lad.
Later, the Fatal Five regained consciousness. They were tied together by Hal Jordan and John Stewart's sturdy ring construct.
"What a touching moment.", Mano said.
"You won this time. But next time, we'll be back! And by that time, we'll make sure we will prevail!", Emerald Empress told them.
The villains struggled, but can't break free.
"Y'all can talk about that, after you get free from our constructs.", Hal Jordan teased them.
"So, do you guys need a ride home?", Flash asked the Legion of Superheroes.
"Can you take us home?", Lightning Lad asked.
"Of course I can. I have just the right tool to send you back.", Flash told them.
"Really? Thanks.", Brainiac 5 replied.
"Can you take the Fatal Five with us?", Saturn Girl asked Hal and John.
"Nightwing, Batgirl. You were awesome. It's nice we got to team up with you.", Brainiac told them.
"You guys rock too!", Nightwing replied.
"So, farewell.", Batgirl said.
The Legionnaires waved at them, as they, along with Ferro Lad's unconscious body, Flash, Hal, John Stewart, and the Fatal Five entered the teleporter and teleported to Central City, where they went to Flash's lab. Flash introduced them to the Cosmic Treadmill. Once again, Brainiac 5 was amazed. The Legionnaires thanked him. Barry now asked Wally's help as they operated the treadmill and ran at lightspeed to open up a portal to 31st Century. At their signal, the Legion of Superheroes, taking the Fatal Five with them, now entered the portal to 31st Century.
"This was one hell of a day.", Flash said, as he wiped off his sweat.
The five Legionnaires returned, and they were surprised to see the mess in their headquarters. Those are Terra Man and his henchmen.
"Good job, Legion.", Brainiac 5 told his other teammates.
"Congratulations, Brainy. You succeeded. You were able to thwart the Fatal Five's plans.", Bouncing Boy told the five heroes.
"What about Ferro?", Chameleon Boy asked.
"My goodness. What happened to Ferro?", Triplicate Girl asked as well.
"He, made the ultimate sacrifice for us.", Shadow Lass answered, as tears once again fell from her eyes.
Dream Girl, Cosmic Girl, and Saturn Girl all approached and comforted her.
"You may have thwarted our plan, but it was at the expense of your friend's life.", Tharok told them.
"You may have survived, but you're gonna face sentence by the Science Police.", Bouncing Boy told them. Later, police forces came to arrest the Fatal Five.
"What? No! You can't do this to us! We have our rights!", Emerald Empress pleaded.
"Not today. Your rights are oppressed.", Bouncing Boy told them.
The scene moves a few months later, with the Legionnaires all looking up to a new statue of Ferro Lad that was built in memory of him.
Characters: Police, Science Police(31st Century)
Legion of Superheroes: Brainiac 5, Lightning Lad, Saturn Girl, Ferro Lad, Shadow Lass, Bouncing Boy, Chameleon Boy, Matter-Eater Lad, Colossal Boy, Cosmic Boy, Dream Girl, Triplicate Girl
Justice League: Nightwing, Batgirl, Plastic Man, Superboy, Supergirl, Superman, Batman, Wonder Woman, Flash, John Stewart, Mr. Terrific, Captain Atom, Dr. Light, Hal Jordan, Martian Manhunter, Rocket Red, Steel, S.T.R.I.P.E., Blue Beetle, Hawkgirl, Hawkman, Shazam, Booster Gold, Fire, Ice, Firestorm, Stargirl
Villains: Kite-Man, Polka-Dot Man, Ten-Eyed Man, Condiment King, Cavalier, Sweet Tooth, Terra-Man
The Fatal Five: Validus, Mano, Emerald Empress, Tharok, Persuader