Lex Luthor

Lex Luthor, a fictional character and supervillain in The CW's Arrowverse, made his first appearance in the 2017 episode "Luthors" of Supergirl, based on the character of the same name created by Jerry Siegel and Joe Shuster, and adapted for television in 2017 by Glen Winter and Greg Berlanti. In the Arrowverse, Lex Luthor is portrayed as the arch-nemesis of Superman. He is depicted as an independent businessman who runs LuthorCorp. At some point, he and Superman were friends, but their friendship ended when Superman refused to embrace Lex's violent and chaotic ideology. Lex then developed an obsession with Superman, resulting in his eventual imprisonment. Later, he perceives Supergirl as a threat and shifts his focus towards her, abandoning his plan to target her cousin.