Tomie by Junji Ito
Some villains are just pure evil. You have The Joker. You have Dio Brando. You have Majin Buu. Then you have...
Tomie is an anthology series about an immortal woman named Tomie and her only purpose in life is to be a jackass. Its unclear what or who Tomie is. A vengeful ghost, a demon, a succubus, a playful trickster god. She is always a beautiful woman with a beauty mark under her right eye, and doesn't appear at any set age. What is clear is that Tomie is completely immortal in the most ridiculous of ways. Tomie cannot die. She has the power of influence over nearly any man to varying degrees of efficiency - sometimes the men try and claim Tomie as only theirs, others grow deeply afraid of her but the result is mostly the same; they kill her, usually hacking her to pieces in the process. All this does is usually make more Tomie that can spawn from her hair, her fingers, her mashed to pieces body. By the last chapter, at least half of the stories end with an army of Tomies marching off somewhere. The last chapters are about three Tomie who eventually go to war with each other and send male assassins after the other Tomie (Tomie is very, very vengeful and envious.) I'm somewhat disappointed that the end of the manga wasn't that every woman eventually turned into Tomie and all the men try and kill them, and then its planet Tomie.
As I said, Tomie doesn't really have a goal. All she does is be a complete asshole for no reason to random people. Tomie will show up in some location and proceed to fuck up everything and cause a swirl of murders and discord centered around her, then leave when she gets bored. Normal happy families, little boys, old couples, high school girls. Nobody is safe from this bitch! If you're lucky she'll just get bored and go somewhere else and you'll just have your nightmares. If you're unlucky, then you're probably dead, in prison or worse.
This is Ito's first serialization, but he had a knack for this all the way back then, although his artwork at times is more akin to Umezu then it is now; especially on cover pages. He still had the penchant for body horror and disturbing monsters.
So Tomie is good. Read it. I'll leave you with my favorite panel -