Vandal Savage/YMMV

Millennia worth of experience may cause variance on the matter, but...

Complete Monster: Millennia worth of murders should certainly count. Plus there's this little statement of his from The Flash Vol. 2, #14:

I used to be France's court physician, you know. I would use the royal family for syphilis experiments...

- He invented cannibalism.
  - He invented evil as a human concept. Is it no wonder he's considered to be Cain?
    - Everyone in the DCU hates him. You won't find many people who would be willing to work for him; hell, you probably won't find many people who wouldn't rather die than be forced to work for him. And if someone is willing to work for him, then chances are very high that they're probably disgusting individuals themselves. He's just that bad.
Foe Yay: Primarily with the Immortal Man and Resurrection Man, but also with Wally West during his stint as the Flash.
Magnificent Bastard: He behaves magnificently, and he's a bastard of a man.
Moral Event Horizon: Considering just how much of a scheming, sadistic, bloodthirsty animal this man is, and the number of centuries he's had to commit his atrocities, it's difficult to say just when he crossed the point of no return (if ever there was one for him); however, any one of the following events are good contenders: destroying the legendary Atlantis through the manipulation of the then-newly-formed Illuminati; razing Montevideo, Uruguay alongside the artificial sun Solaris in a plot to assassinate Superman-Prime; kidnapping a little girl and burying her alive in a booby-trapped graveyard in an attempt to kill the Flash; orchestrating the near-rape of his daughter; putting a hit on the lives of the Secret Six to blackmail Scandal into producing an heir for him...of these and other moments, take your pick.
My Real Daddy: Christopher Priest, usually. Priest's Savage had a lot more depth than most iterations, and was arguably the most Magnificent Bastard in all of the DCU.
Older Than They Think: Ironically, Wizard magazine, the most "mainstream" magazine on comic books, once contemptuously referred to him as "a cheap Ra's al Ghul knockoff". Actually, Vandal Savage predates Ra's by twenty eight years-—Savage first appeared in 1943, while Ra's appeared in 1971.