Imperiex

He also appeared in the second season of the Legion of Super Heroes animated series, as the main villain. He traveled from the 41st century to conquer the galaxy. Unlike the Imperiex in the comics, there isn't anything cosmic about him. His alternate origin is that he's an alien raised in a gladiator lifestyle, and over time his body was modified by technology that allowed a perfect union of organic tissue and cybernetics. In part 1 of "Dark Victory" he was killed by the evil Brainiac 5 and takes over in his place to put his ancestors plans of order to fruition.

Histroy
The reputation alone of the star-spanning Imperiex was enough to instill fear in the heart of Mongul the Second (especially when the called "Destroyer of Galaxies" decimated the Warworld). With Imperiex on a collision course for earth, Mongul formed an uneasy alliance with Superman so that he might suitably train the Man of Steel for deep Space combat to halt Imperiex`s swath of destruction. In a pitched battle, Mongul and Superman prevented Imperiex from assembling an Energy vortex designed to erase Earth`s solar system. But Imperiex disappeared, leaving the Man of Steel to defeat Mongul. Unfortunately, neither Mongul or Superman realized that the foe they faced was merely a probe in the service of the true Imperiex, a decidedly larger and more powerful being who has focused his attentions on the Man of Steel. Imperiex Prime wields the power of the Big Bang itself. Wanting to destroy the present universe and create a new and more perfect universe, Imperiex Prime sets out to destroy the universe world by world. When Imperiex arrives at Earth, the hero's and villain's of the world unite as one to fight him off. Kismet and Superman managed to crack Imperiex Prime's armor, but Kismet was killed during the attack. Superman, with help from many other heroes, manages to send Imperiex Prime's consciousness, Brainiac 13 and Warworld back 14 billion years in time to experience the Big Bang. The instant before Imperiex dies in the explosion, he realized that the flaw in the universe he had come to erase was himself.

Over 8 million on Earth were killed during the attack on the planet.