All I know is, it better be an absolute A list actor who understands Lex Luthor.
Lex luthor is the greatest villian ever, because as I've said on here, he is actually RIGHT. Superman would be a menace on earth and he makes humanity less important and relevant. Luthor is the wealthiest and at worst, 2nd smartest person on earth (Sivana might be smarter) and he is nothing compared to the alien. IMHO outside of his world domination efforts, everything he does to undermine superman is just. He is a very deep charactor and outsmarts superman and uses his code of ethics against him all the time. The actor should be forced to read every relevant version of luthor and especially read Lex Luthor Man of Steel, watch and read all star superman (TPB and movie), read the entire LEX:2000 arc, watch justice league and unlimited, and watch Spacey's portrayal of luthor.
This is the second most important casting of the series. If they botch this with BILLY ZANE or someone, I'll explode.