Shou Tucker, the bullies from Elfen Lied, Richard Cameron, Malty S. Melromarc, Seryu Ubiquitous, Chaka from Black Lagoon, Ralph Cifaretto and Suguru Kamoshida would be a few...

Percy Wetmore from The Green Mile and Commodus from Gladiator.

^^ A few of those actually have some of my sympathy and pity. But I won't list names.

Valentino from Hazbin Hotel. He makes everyone else here seem like a saint.

Homelander from the Boys is a nasty piece of work

Theo Galavan from Gotham

Aunt Marge

Also Ridley (especially in the manga)

Judge Claude Frollo.

I actually found Frollo pretty cool, but i do understand your answer.