I'll give them the benefit of doubt. But I wouldn't like if they chose a mad man to try and top Kefka. It doesn't work that way.

Make some kind of deviously cunning strategist, always steps ahead of the main characters and that he continuously screws them up in the worst way possible and I could concede. I doubt they will, though.

Theatrical. Very good no one went this route. 

You can laugh it off, but it's the truth. Hojo impregnated Lucreita. Infused Sephiroth with Jenova's cells in womb. Experimented on Vincent etc. etc. 

HA! My bet is on "no he is not".

Even if he is, his status wont be recognised for years to come. Seph and Kefka aquired legendary status.

I like that he is very optimistic but selling hype almost never ends up well.

Such as? Please tell me all of his false promises....

and honestly, Sephiroth and Kefka aren't super high bars imo. Sephiroth especially as he wasn't an actual villian.

Wanna make the best villain? Make him/her practice eugenics on the populace.

Kefka is one of the most deceitful, evil, deranged and sociopathic villains. Plus he's oddly likable. He's gonna be tough to top.
Sephiroth is good, but he's mostly just high up because of the "cool" factor. He is actually a fairly one dimensional and relatively shallow character. I enjoy the game, but both Cloud and Seph aren't the best parts of it.

Of course he was.  If you're referring to Jenova:  Any claim that Jenova was in control is debunked by the Jenova Reunion incident, which saw Jenova's body being controlled by Sephiroth and made in his image coming to the Northern Crater, where the real Sephiroth resided.  Why would Jenova do what Sephiroth wanted?     http://finalfantasy.wikia.com/wiki/Jenova

Just CTRL+F and search "control"

I know the story.