BEGIN SLIDESHOW Lex Luthor to Appear in Supergirl Season 4, Plus First Look at Lois Lane Deadline reports that Superman’s biggest mortal enemy Lex Luthor is making his way to National City as Supergirl executive producers Robert Rovner and Jessica Queller announces his forthcoming appearance in the fourth season of The CW’s DC superhero series. “We’re beyond excited to introduce iconic villain, Lex Luthor, to Supergirl and to weave him into our story this season,” Rovner and Queller said in a joint statement. “We’ve talked about having Lex on the show since it’s inception and we’re excited to have him finally arrive.