IMPERIEX!

A new and dangerous foe emerged from beyond the cosmos to threaten the Man of Steel and all he held dear. Imperiex, the Destroyer of Galaxies, was that threat, and his reputation was considerable indeed. Maxima of the house of Almerac, whose fighting skills were as legendary as her lust for the Man of Steel, faced against this mysterious being and lost. Superman was warned of Imperiex's coming by the Eradicator, which had seen the devastating results of Imperiex's contact with other systems. Even Darkseid, despot lord of Apokolips, said Imperiex's name with awe and fear.

Mongul the Second, son of the despot who ruled the planet-sized engine of destruction known as Warworld, came to Earth to seek out Superman's aid. Actually "came to Earth" is a misleading term; the truth of the matter according to Mongul (a dead ringer for his father) was that he had been thrown to Earth from space by Imperiex after Imperiex destroyed Warworld.

Mongul persuaded Superman that the threat posed by Imperiex was very real and very imminent. Superman agreed to let Mongul train him, to teach the Man of Steel ways to tap into his deepest power reserves. The forthcoming battle with the Destroyer of Galaxies would require that Superman be able to give his all and then some.

Mongul and Superman travelled into space and faced off with Imperiex. The battle was indeed tremendous, and through it all Imperiex's impressive engine of destruction moved slowly, inexorably towards the earth. Finally Superman realized that instead of destroying Imperiex, the best course of action was to destroy his ship.

The loss of his machine forced the being Superman and Mongul had fought to retreat. It returned to its home, where it was revealed that this being was not the real Imperiex but instead merely a drone, a scout sent ahead to study the galaxy. The real Imperiex was in fact a much larger entity, and his probe's defeat at the hand of Superman caused Imperiex to target that system for total destruction.

Some months after Lex Luthor was elected President of the United States, Imperiex arrived in the Earth's solar system. Imperiex sent several probes ahead of itself, targeting the planet Earth for total destruction. Superman and the entire Justice League rallied with the rest of Earth's heroes to do battle with these probes. Although they managed to discover a way to destroy the probes, the knowledge came at a heavy cost. The destruction of one probe led to the devastation of Kansas. The destruction of another resulted in the disappearance of Aquaman and his kingdom of Atlantis. And Major Sam Lane, President Luthor's Secretary of Defense and Lois Lane's father, sacrificed himself to destroy a probe headed for the White House.

When the Justice Society of America flew to deep space to battle Imperiex Prime, they managed to disable his ship, stopping Imperiex from creating any more probes to send to Earth. When that happened, Imperiex Prime engaged in battle directly. Imperiex Prime was much more powerful than any of the probes which Earth's heroes had fought. It seemed hopeless.

At the last moment, when it seemed certain Imperiex Prime would succeed in destroying the Earth, Brainiac-13 reappeared, in control of a new Warworld. Using Warworld's energies, Brainiac-13 captured Imperiex, intent on using Imperiex's universe-destroying power to its own ends.

When Superman flew to Warworld, intent on destroying it, he realized the quandary: if he destroyed Warworld and defeated Brainiac-13, he would release Imperiex, who would then destroy the universe.

With the help of Darkseid and Luthor's control of the B13 technology, Superman was able to transport Warworld, Brainiac-13, and Imperiex to the beginning of time, where all three were ensnared in the massive energy release of the Big Bang.