Joker is great because it's using a well known character, but it could be literally anyone. From what I remember, the movie essentially had nothing to do with what Joker will become besides showing how it becomes that. There's no supernatural things. No powers or special abilities. He's just a guy. A guy who ends up being a character we all know, but he isn't yet.

It's using the marketing appeal and budget that DC stuff automatically gets, but it's using it to tell a story that is almost outside of it.