Born into the realm of the pocket universe, this Lex like his Earth-One counterpart admired his native universe's Superboy from afar. But unlike the teenage Earth-One Luthor, this Luthor was never able to meet his Superboy while the Boy of Steel was alive. Thus, this Luthor incarnation was spared the accident and disappointment that turned the Earth-One Lex against the Earth-One Superboy.
After a long absence when the Kents revealed that their adopted son was indeed Superboy and assumed him to be dead, Lex finally traveled to Smallville to express his true feelings of loss to the Kents, only to come across Lana Lang and Pete Ross who were mourning the deaths of the Kents. Offering his help to find Superboy, Lex Luthor used one of the Boy of Steel's inventions inside his secret underground lab to try finding him and accidentally accessed the Phantom Zone, where he let loose three dangerous criminals who proceeded to terrorize the world.
Though Luthor found out about the hidden canisters of Gold and Green Kryptonite in the lab, he chose not to use them due to the same pride issue his New Earth counterpart had with Superman: he wanted the defeat of the Phantom Zone criminals to be by his own hand. To that end, Luthor put his scientific genius to use for benevolent purposes: aiding the defense of humanity, creating a resistance team that included non-powered versions of Bruce Wayne, Hal Jordan, and Oliver Queen. When Lana Lang died, Luthor created an artificial being made of a protoplasmic matrix that he gave powers to as well as memories and the appearance of Lana Lang. This created lifeform would become Supergirl.
Realizing that his scientific creations were not enough to stop the Phantom Zone criminals from murdering the human populace with casual disregard, even to the point where they instantly annihilated all people except those in the Smallville citadel, Lex decided to recruit the known other-dimensional Superman to aid the heroes native to his Earth. To that end, Luthor sent his created Supergirl through the dimensional void, blanking out her memories but implanting in her a compulsion to go to Metropolis where her memories would slowly return. He also transported her to appear several centuries in Antarctica, believing that Superman also had the ability to travel through time and thus would find Supergirl during his time travels. However, since that was not the case, Supergirl remained buried until a group of scientists uncovered her body in the present time, where she slowly recovered before heading toward Metropolis.
As she had a confusing run-in with Superman on her way to finding him, Matrix Supergirl would recover her full memories and transport herself and Superman back to the pocket reality Earth, where Lex Luthor filled in Superman with all the details of what had transpired. Superman, along with Supergirl, Lex Luthor, and his resistance team confronted the three Phantom Zone criminals as they engaged in a battle that resulted in great disaster: the Smallville citadel was destroyed, all of Luthor's team members were killed, and Supergirl was surprisingly melted. Lex Luthor secretly told Superman to head towards Superboy's underground lab while he tended to distracting the Phantom Zone criminals. In the lab, Superman found a hidden lead canister that contained the Gold Kryptonite and exposed Quex-Ul to its radiation. Turning the underground lab into a prison and hiding the Gold Kryptonite sample in his cape, Superman also depowered General Zod and Zaora and captured them, letting them languish while he went to find Lex Luthor, who was now mortally injured.
Before passing away, Luthor revealed to Superman the truth about Supergirl and the fact of his own pride getting in the way of using the Kryptonite to stop the Phantom Zone criminals for good. Luthor made Superman swear that he would not let the same disaster that befell his world take place on his own and so, faced with a difficult decision of what to do with three depowered evil Kryptonians who had committed genocide on a global scale, the Man of Steel chose to execute them by fatal exposure to Green Kryptonite, watching sadly as all three of them fell. Superman could neither leave the Phantom Zone criminals powerless to die from asphyxiation on the world they had destroyed, or take them back to his own universe to face punishment there: a Pocket Universe was out of the jurisdiction of the Metropolis Police Department or any other authorities, and General Zod had boasted that he, Quex-Ul, and Zaora would find a way to get their powers back — if this had happened, no force on Earth could have stopped them. Afterwards, Superman swore that this would be the last time he would kill other living beings.
Lex Luthor was buried on his native Earth, and Supergirl was taken by Superman into the New Earth reality where she would recover.
- Lex possessed hundreds of thousands of devices that he directly created himself, as well as enhanced and assisted in creating mostly from his native dimension's Superboy, including his most noted creation, Supergirl ("Matrix").
- 5 Appearances of Lex Luthor (Pocket Universe)
- 2 Images featuring Lex Luthor (Pocket Universe)
- Quotations by or about Lex Luthor (Pocket Universe)
- Character Gallery: Lex Luthor (Pocket Universe)