Billionaire, Alexander Joseph "Lex" Luthor is Superman's greatest enemy. Not being endowed with superpowers, he uses his intelligence, his oversized ego, his money, and all ressources he have to set up sophisticated traps.
For exemple, during the "No Man's Land crisis", Lex Luthor tries to illegally take over Gotham City's properties. His plan fails thanks to Bruce Wayne and Lucius Fox.