Kefka turns into Lucifer for the final battle.

When I told Lucius that I was going to put Kefka as my BotW this week his first words were, "...anybody who doesn't like Kefka is an A-1 cock and an Anti-Kefkite bastard".  I would also like to add they they're probably baby-eating, puppy-kicking terrorists who hate America as well.

Kefka Palazzo is the diabolical villain from the game Final Fantasy VI (Final Fantasy III in the U.S.) and one of the biggest pixelated bastards to ever grace the video game industry with his presence.  He's mean, evil and cunning (but also strangely likeable and humorous), and he would play a major part in redefining the role of a video game bad guy.

Kefka was different from most villains before him because he starts out the game as a minor lackey to the Emperor Gestahl.  Kefka basically travels around serving as a General in the Imperial Army, doing crazy badass shit like pissing off the heroes, setting everything on fire and poisoning the water supplies of castles that challenge the Empire.  However, once Kefka realized he had the opportunity to seize ultimate power later on in the game, he made a grab for it, killed the Emperor and ascended to godhood, smiting everyone in the world who failed to worship him as a deity.

Kefka is completely out of his mind, and is one of the greatest bad guys in video game history.  When your party confronts him at the end of the game they give him some bullshit speech about how they've come to respect life and all this lame-ass crap, Kefka just responds with something like, "What the fuck?  You sound like a damned self-help booklet!".  When one of his Generals betrays him, he just flips out and yells, "I HATE YOU" about twenty times in a row (an interesting note is that in the Japanese version, instead of "hate" he says "fuck", which is even more badass).

Kefka's awesome.  To try and explain why here would do him a disservice.  You just need to play Final Fantasy VI for yourself.  Plus, then you'll also hear his badass theme song.