Kefka

From KefkaPedia

Kefka is THE villain from Final Fantasy VI. Wherein most villains are content with just defeating the protagonist, he wanted to destroy happiness in general. In Doma, for no reason other than pure maniacalness, he poisoned the water, killing almost everyone in the kingdom. He seemed to just like building up this giant group of enemies. He was eventually defeated, but, he has gone down as one of THE most evil villains in the history of anything, although Seymour comes close. But, he was just insane. Then again, so was Kefka. XD