Camus. One of the two main schools of existentialism, one of his largest works is about motiveless murder as an outcry to find meaning or lack thereof in life. Kefka specifically states he wants to destroy the world to prove that it does not.
He’s an existentialist villain, essentially, instead of a hero. Instead of asking the question, he’s decided on the answer and out to prove it by experiment. More misanthropic, same idea.
Sephiroth, again, sat in a goddamned crater and whined.
) And the music is still epic.