Dont know if this is real, I think its too soon, so it is probably fan art. But Damn, I like it.
Someone made a post in a movie forum I go to about the Villain being the city in the 3rd film, it was something like...
In Begins he fights to save the city's lives, in the 2nd he fights for the souls of the city, and in the 3rd he will fight the very people he protects.
Could make sense. He is now thought of as a Villain, and to go with The Mackem, maybe the Riddler is a genius(always) obsessed with Batman, and ascends to power in the city trying to catch him.