Brainiac 5 and Superman take on an army of flying alien warriors, the Dominators. Brainiac 5 takes a serious injury protecting Superman and crashes to Earth, while Superman goes on to defeat the other warriors at superspeed. Superman expresses his admiration for the dying Brainiac 5… and the simulation ends. The other Legionnaires give Brainiac 5 a hard time for spending excessive time with the simulation Superman. They're interrupted when a portal opens and a figure in a dark red costume emerges and proclaims himself as Superman.
The newcomer demands that the Legion follow him but the team isn't impressed. He says that 41 trillion lives hang in the balance and the team decides to go with him through the portal: New Metropolis in the 41st century. An army attacks and the new "Superman strikes back at them. The other Legionnaires rise to the challenge but the newcomer has to help against what he identifies as the Imperiex army. Brainiac 5 isn't impressed with "Superman's" lack of teamwork and in turn he is suspicious of Brainiac 5.
A new robot approaches which Superman identifies K3NT, his "creator." K3NT explains that the Legion defeated tyranny throughout the galaxy but a new evil arose, Imperiex. K3NT discovered Superman DNA and created Superman X with invulnerability to kryptonite. He was unable to defeat Imperiex and they used a time travel device to send him to the 31st century to get the Legion to help them. Imperiex is now closing in on their secret resistance base and the Imperiex army approaches Earth. Aboard his fleetship, Impexiex addresses his forces, telling them now is the time to wipe out the past and build a new future.
Superman X takes them to resistance headquarters but the Legion suggests they need a plan. Brainiac concludes he has one weakness, his cannon blast. It exposes his energy core so that a magnetic pulse missile can take him out. Superman X agrees to do it their way. Imperiex attacks and Superman X, the Legion, and the rebel resistance open fire on his troops. Imperiex prepares to fire his chest cannon but Superman X knocks it aside. the two fight and Superman X is knocked down, but Brainiac 5 emerges and fire his magnetic pulse cannon, blasting him back The Imperiex army withdraws but Imperiex wakes up and knocks them aside, taking Superman X's warp key. He escapes into the 31st century and Brainiac 5 admits he must have accessed an energy reserve.
Brainiac 5 figures he can build another warp key but warns it will take a while. The universe starts to collapse in waves of antimatter as Imperiex rewrites history. K3NT confirms that Imperiex's energy cruiser should allow them to open a portal to the past, before it is wiped out by antimatter waves. Superman X and the Legion go to the ship's engineering system and Brainiac 5 goes to work, although Superman X is still leery of his aid. The other Legionnaires fight Imperiex's destructo-bots.
Antimatter waves began to overwhelm the ship and Triplicate Girl merges together to take on a destructobot. She splits up again… and one of her bodies is pulled into the antimatter wave. Superman X and Brainiac 5 fight over their respective issues while creating the time portal, but the engine overrides kick in and Brainiac 5 tries to deal with them. A destructo-bot attacks and Superman X holds it off but is knocked through a floor by the robot. The rest of the Legion arrive and head for the portal, but Superman X re-emerges and joins them just in time. They return to the 31st century… and find Legion Headquarters in ruins. (to be continued)
Reep Daggle of the planet Durla first appeared in Action Comics
#267 (August 1960) and was created by Jerry Siegel and Jim Mooney. Reep shares his people's ability to shapeshift into any form they can imagine. It was eventually revealed that he was the son of Legion founder R.J. Brande, himself a covert Durlan. Chameleon Boy has served with the Legions steadfastly in several incarnations and leads the Legion Espionage Squad. He has gone through minor changes in several reboots and as of the time this episode aired uses the name "Chameleon." Reep can shapeshift into other forms but cannot duplicate superhuman abilities, and can alter his size from that of an insect to gigantic creatures.
In the WB animated universe, Chameleon Boy first appeared in the Superman: The Animated Series
episode "New Kids in Town"
where he was one of three Legionnaires sent back to contact Superboy. He later appeared in the Justice League Unlimited
episode "Far From Home"
as a mind-controlled pawn of the Fatal Five.
Imperiex first appeared in Superman
#153 (February 2000) and was created by Jeph Loeb and Ian Churchill. Imperiex Prime is a creature of pure energy embodying the Big Bang who sought to recreate the current imperfect universe. After wiping out countless planets, he came for Earth and the heroes and villains were forced to ally together to stop him, although over eight million Earthlings and countless aliens on other planets were wiped out. Eventually Imperiex Prime was sent back to the Big Bang where he became the very imperfection he sensed. This is his first appearance in the animated universe.