[Varyon]

Thinking of some web serials, Jack Slash from Worm was a fascinating villain. A decent (albeit often twisted) sense of humor and a surprisingly-charming demeanor, but an absolute sadist and master manipulator who managed to lead a group of markedly-more-powerful* individuals than himself. Morgunov the Mad Demon from The Zombie Knight Saga (currently on one of its extended, unannounced hiatuses - hiati?) is also interesting, a tinkerer with, again, a peculiar sense of humor (one of his inventions is a vending machine that you pay for with pain and potential maiming**). You'd need some fairly powerful characters to be able to be any sort of threat to him, however.

*As is eventually revealed, while his known power isn't great (but isn't terrible either - he can use any bladed instrument to strike from a distance; he favors straight razors and knives, but does use swords or - on one occasion - basically rides another super who is largely made of blades), he has a more subtle one that basically lets him detect nearby supers and what they're doing (and probably how their powers work), which likely contributed to his longevity.

**"A slap to the face for a pack of gum seemed fair, as did a boxing of the ears for a bag of chips and a purple nurple for a candy bar. He wondered if anyone would go for the bag of mini-donuts, though. Maybe a needle in the eye was too much to ask."