Nebula - Definitely prefer her as a protagonist, I mean she's one of my favorite MCU characters.

Fecto Elifus - Probably the coolest design of any Kirby villain ever? Also a super horrific concept, that is executed perfectly.

Negaduck

Negaduck - Poggers

Sephiroth

Poggers?

Sephiroth seems really cool, although I have never played Final Fantasy

Fire Lord Ozai and Gendo Ikari

Ozai - Very intimidating and whatnot. Not super deep, but he doesn't need to be. He works as he was.

Rex Dangervest

Cassandra (Picos School)