The ultimate villain: Ansem Sephiroth . . .
. . . . . . . . . Handsome Sephiroth?
What is Ansem's weapon again? Besides his "guardian" :rolleyes2 ?
Haven't put requisite time into FF6 despite owning it, but from what I've heard, Kefka was quite the psycho. Sephiroth went all mega-maniac when he learned he'd been "created" as opposed to being born and decided merging with the planet was his destiny. Ansem discovered shadow creatures under his castle (which he called "Heartless"). He was researching the heart and the darkness within and his obsession became the desire to "open the door to darkness." I'd call that idiocy as opposed to psychosis.
Overall, I can't really :D anyone of them. I don't know what Kefka was thinking, Sephy had the right idea but the wrong plan, and Ansem is just a complete idiot. "Seeker of darkness." Seeker of fecal matter.