The embodiment of entropy, Imperiex takes the form of pure energy contained inside a humanoid set of armor, colossal in size. Since the dawn of time, he has repeatedly destroyed the universe to create a new one from the ashes of the old. He is first mentioned when Mongul II arrives on Earth stating that Imperiex has destroyed his Warworld and is heading for Earth. Mongul convinces Superman to help him fight Imperiex, and the two apparently manage to defeat it. However, it transpires the "Imperiex" they encountered was nothing more than a probe of Imperiex Prime, the real Imperiex who is a much larger and more powerful being. He has detected imperfections in the fabric of the universe, and his ultimate plan is to destroy it and create a new, perfect one. To do so, Imperiex Prime heads for Earth, the planet which holds the universe together after being the center of the "Crisis on Infinite Earths", to destroy it and thereby induce a new Big Bang.