Created by Marv Wolfman and George Pérez, the character made his first appearance in Crisis on Infinite Earths #1 (April 1985).

He had a prominent role in that series, and appeared 20 years later as one of the two primary antagonists of the sequel Infinite Crisis, alongside Superboy-Prime.

[1] Luthor Sr. is Earth-Three's only hero, fighting the Crime Syndicate (an evil version of the Justice League of America).

Alexander becomes colder and more detached from the well-being of the universe's living beings, progressively becomes as corrupt as his father's villainous counterparts.

Alexander also reveals that his presence on Earth is what has been causing Lex' recent erratic behavior and interference to his thought processes.

[16] The device requires a vast power source to operate, which Alexander generates by manipulating the Spectre into destroying magic.

With sorcerers dead, the result is a raw form of magic that he device can tap into; this is personified by the power commanded by the wizard Shazam after his death.

At the center of the universe, Donna Troy and her team see gigantic representations of Alexander's hands creating a rip in space.

[18] As Alexander attempts to combine Earth-Two and Earth-Three, Firestorm converts all the energy the heroes are firing at the rip into positive matter.

[22] Alexander's greatest talent is his genius-level intellect which he uses to manipulate other characters, outwit his enemies and engineer the Multiverse Tower.

The circumstances of his escape from the doomed Earth-Three give him power over matter and anti-matter, which he can use offensively as bursts of energy or to form and control dimensional portals.