After Intergang killed Lois Lane by blowing up her car, Superman, stricken with grief, forged an alliance with Luthor, believing that ruling Metropolis was the only way to keep everyone safe. With Lex's help, Superman took over Metropolis and co-ruled it as a dictator, Lex helping enforce his and Superman's rule by making Mercy the head of the police force. Unknown to Superman, Luthor was secretly abusing his power by imprisoning rebels in horrible conditions and separating them from their families.
After the mainstream Lois Lane accidentally transported herself to Lex's universe, Mercy found her and brought her to Lex when she busted into the revolutionaries' hideout. After realizing that Lois was the genuine Lois Lane, Lex, knowing that Superman would cut off their alliance if he realized that she was alive, had Mercy take Lois out in the streets to be killed. After Mercy fails to kill Lois and she is discovered by Superman, she takes him to the prison where Luthor had been holding the rebels and shows him what he had been doing without his knowledge. Betrayed and enraged, Superman, along with Lois, rushed back to Luthor's office and confronted him on what he had been doing. However, Luthor then takes out a large chunk of Kryptonite and beats down on Superman, telling him that he is going to tell everyone that he was forced to imprison them and make himself out to be a hero. Just then, the rebels enter Luthor's office, revealing that Superman had freed them and told them the truth.
Cornered, Lex ran away to his aircraft and flew away but Superman followed him. When Superman tried to get Luthor out of his aircraft, Lex used his Kryptonite on him, causing Superman to damage the aircraft's jets before losing his grip. As the aircraft began to fall, Luthor pressed the eject button, only to realize that it malfunctioned, leaving him stuck as the aircraft crashed into his statue, killing him and causing the people of Metropolis to rejoice.