I read somewhere that the possible villain for Batman vs. Superman might be Metallo. Which I think would be a good pick for both of them. Mostly because, at one point in the DC universe, John Corben was suspected of being the man who killed Thomas and Martha Wayne, a ruse created by Lex Luthor. He’s a new villain that hadn’t been done before and he has ties to Superman and Batman. I also heard rumors about Joaquin Phoenix possibly playing Lex Luthor, and a separate rumor that Luthor will appear in the series in very small roles like how Nick Fury did for the Marvel movies. I can see Metallo used as a way to take out Batman and Superman by Luthor who remains in the shadows until we can actually see the Man of Steel face his arch enemy greatly. I just really don’t think Luthor should be the villain in Bats vs. Supes, the rivalry between Supes and Lex match Batman and Joker, and you don’t want Bats to ride their coat tail, or should I say cape tail.
Plus, I picture the end of the story, where Batman will make his way to Metallo to kill the man who killed his parents, and is going to do it too. But Superman convinces him not too, because after Superman killed Zod it left a stain in his heart that he can’t live with and doesn’t want Batman to live with that as well.
I just think it works.