Batman: Darkest Night - Joker

For a few months, I've been working on a personal project based around an idea for a Batman movie.
This is my concept for the Joker. I know some people will disagree with my casting choice here but...I seriously believe Matthew McConaughey would knock it out of the park as the Joker. Imagine Heath Ledger's Joker had a baby with Rust from True Detective - that's how I see the Joker. A bitter, nihilistic, psychopathic agent of chaos trying to reveal the true face of society. In the story Joker is being used by Dr. Hugo Strange and, in a twist at the end, finds out the true identity of Batman. However he keeps the secret as it would spoil the fun for the future.
"Secrets that are mine alone to know... Bruce. It's true! I know everything. And kinda like the kid who peeks at his Christmas presents, I must admit, it's sadly anti-climactic. Behind all the sturm and batarang, you're just a little boy in a playsuit, crying for mommy and daddy! It'd be funny if it weren't so pathetic."