Why So Serious, Kim?

Kim has faced insane villains before...but never of this caliber. This man called 'The Joker' is violent, yet conniving. It also looks like he's planning something...but what? Whatever is it, Kim will have a big sitch on her hands dealing with this enigma...more than she ever knows. (TDK Joker/Kim Possible crossover fusion) Rating will go up.