Lex Luthor is a character that appeared in Justice League: Crisis on Two Earths . He is a hero that came from a parallel universe where the roles of heroes and villains are reversed.
Lex Luthor was the leader of the Justice League on the Earth universe inhabited by the Crime Syndicate. However, the decimation of his team by the Crime Syndicate left him and the last known surviving member of the Justice League, the Jester, to break into a Crime Syndicate stronghold to steal the quantum trigger, a device that the Crime Syndicate intended to use with their quantum-powered nuclear missile to destroy all known life on Earth. Lex Luthor used a transdimensional device to transport himself to the universe inhabited by Superman's Justice League to get his team's attention and help in defeating the Crime Syndicate. Luthor hid the quantum trigger on board the Justice League Watchtower satellite in the hopes that the Crime Syndicate would never find it. However, Superwoman used a copy of Luthor's transdimensional device created by Owlman to transport over to that dimension and retrieved it. Luthor later explained to the Justice League that without the quantum trigger, they would have had the upper hand against the Crime Syndicate. When Owlman transported the quantum nuclear missile to Earth-Prime in the hopes of destroying all realities, Luthor and Johnny Quick helped Batman cross through dimensions to stop Owlman, having him and the missile be transported to a cold desolate Earth universe where it would destroy that Earth without harming anyone.