court of owls , i know they are new but it would be amazing to see them fight batman on the big screen . red hood too complicated to go through , deathstroke is more of a titans villain in my eyes . (batman has enough villains why take slade too? lol) hush is doable , ivy and freeze had their chance . grundy ,croc, and clayface are goons . they can't hold a movie all by themselves . riddler (while already appearing in a bat film) can also hold his own , especially if he jigsaw-esque .
How about Dr. Simon Hurt? In fact, I'd have him be the primary antagonist over the course of a new trilogy which borrows heavily from Grant Morrison's epic run, with the first film also featuring Lincoln March and the Court of Owls. Such would allow for a strong focus on the family dynamic, with Bruce dealing with the loss of his father, Thomas Wayne, by struggling against two adversaries who claim that name for themselves (Thomas Wayne Sr. and Thomas Wayne Jr).