I'd replace the Delightful Children with Father, I don't agree with Eris instead of Nergal or Boogie entirely, but more females I guess. I'd drop Jake and Adam for Dick Dastardly as well and merge Finn and Jake to make room for AKU. Cow and Chicken should just be SUPER COW, and I'd drop Clarence for any Ben 10 villian.

Drop Johnny Test for Quest as well. Into a fire.

I'd complain about some of the characters here being nonsensical or inappropriate to include, but then I remember that the actual Cartoon Network fighting game had Captain fucking Planet.