Imperiex made Mongul fear him.After Imperiex destroyed Warworld Mongul asked out of all people Superman to help him.

Imperiex Prime devoured Mongul's planet and wanted to consume the center of the universe to create a new and better universe. The center of the universe is Earth. After devouring several other planets, Mongul and some other survivors like Braniac 13 bounded together and chose to join the superhumans on Earth to defeat Imperiex Prime. After destroying many probes of Imperiex Prime, Imperiex Prime then began his attack on Earth. Lex Luthor freed Doomsday and used him to destroy all of Imperiex's probes until the Imperiex Prime himself was drawn to the battle. Imperiex Prime easily defeated Doomsday and Imperiex projected a powerful blast of energy hich completly destroyed Doomsday. The

superhumans then sought a way to break through Imperiex's armour. The Strange Visitor and General Sam Lane sacrificed themselves in order to let the superhumans on Earth break through Imperiex's armour.Darkseid then used his advanced technology to transport Imperiex Prime's energy but Imperiex's energies were absorbed by Brianiac 13. With Imperiex's powers, Brainiac 13 claimed that he would use his new found powers to conquer the universe.

Superman eventually gains more strength. Superman realizes that Warworld could not be destroyed because of Imperiex Prime's powers running through Brainiac 13. Superman and Martian Manhunter develops a new plan and succeeds in sending Imperiex Prime and Brainiac 13 back 14 billion years ago when the Big Bang happened. The energies of the Big Bang eventually vapourizes both of them. Imperiex Prime at last understood what was the imperfection of the universe, the imperfection of the universe was himself.

The Imperiex War ended when Imperiex Prime died. However, the war caused several superhumans like Doomsday to die. Heroes like General Sam Lane and Maxima also died in the war. Other metahumans like Aquaman and Steel have all been presumed dead. Nearly 8 billion of the world's population was ruinned by the war.