Who becomes a supervillain in the episode that precedes Simpsons Already Did It in South Park ?  
Simpsons Already Did It:  In the episode, which continues on from the events of the previous episode "Professor Chaos", Butters thinks up a series of schemes to take over the world, but realizes that each one has already been performed on "The Simpsons". Professor Chaos:  The boys hold a contest to try to find a replacement for Butters, who becomes a supervillain after being fired from the group as the replacement Kenny.
i don't know