The entire casts of Riki Oh and Violence Jack. Just read them, you'll see what I mean.
Dio Brando from Jojo's Bizarre Adventure (especially in the manga), who also deserves mention for the best ever use of a senator as a projectile weapon. He incinerates live dogs, poisons his father and foster-father, gives Jack the Ripper super powers, and uses the ability to stop time to mess with people for no real reason, just to give a few examples.
The president of Earth from Captain Harlock (the original), who cares more about horse races than invading aliens, along with the entire Earth military, who have nothing better to do (despite said invading aliens) than devote all of their resources to tormenting one small orphan girl.
Any character written by Kazuo Koike.
M.D. Geist.