Earlier this week, James Gunn cast David Corenswet and Rachel Brosnahan in his upcoming “Superman: Legacy” as Clark Kent/Superman and Lois Lane. But who will play Kal-El’s main adversary, Lex Luthor, in the first DCU film? According to reports, it’s down to Alexander Skarsgård and Bill Skarsgård to play the villainous mad scientists/CEO.