Finding himself being offered the Entropy Aegis armor by Darkseid, John Henry Irons appears in space just in time to offer Superman help in trying to stop Brainiac 13 from taking over the universe (MOS #117). After defeating both Imperiex and Brainiac 13, John Henry Irons and Superman conducted tests on the Entropy Aegis to guage its full power, enabling Steel to appear in Superman's defence when he was abducted from time and space by the Linear Men to stand judgement over his involvement in stopping Imperiex (MOS #118).
Long ago, the alien race of beings called the Celestials conducted genetic experiments on humanity of the planet Earth. The gods that looked after the Earth knew that with the Celestials eventual return, there would be a judgment that would seal the planet’s fate. If humanity was deemed unworthy of life, by the unknown standards of this mysterious race, Earth would be destroyed. The Destroyer was created, by the command of Odin, as a weapon to use against the mighty Celestials. The task was taken on by the finest craftsmen of Asgard, and once finished Odin, Zeus, and all other leading Earth gods transferred a portion of their power into the construct which gave it superhuman strength and energy manipulating powers. Odin then had the Destroyer sealed within a temple within a plateau hoping it would be out of reach of any would use its tremendous powers for evil until the purpose it was designed for could be implemented.