There's more to being an anime villain than just doing bad things. The most truly disturbing anime villains are the ones that just creep you out. These unsettling antagonists in anime can be freaky for myriad reasons. Sometimes, that creepy villain panache involves vomiting up snakes, which vomit up clones of yourself, which vomit up more snakes, which vomit up swords, like Orochimaru from Naruto.
Sometimes it involves becoming so obsessed with how another person smells, you kidnap him and try to eat his flesh in a gladiator arena, like Shuu Tsukiyama from Tokyo Ghoul. Sometimes, it just involves being a teenager who makes other teenager's bike racing experiences less fun. That might sound petty, but if you're a truly weird anime villain, like Akira Midousuji from Yowamushi Pedal, you can be every bit as unsettling as any fictive mass murderer. Check out these chilling villains in anime, and try not to shudder too hard.
If you've heard of Fullmetal Alchemist: Brotherhood, you probably know what's coming (certainly, there has been no shortage of memes on the topic). Shou Tucker is a state alchemist, who won his position by creating chimeras that can talk. Or, pretending to, anyway. Actually, he created them using alchemy to fuse his wife and his daughter with dogs, permanently destroying every being involved.
So, why is he more unsettling than, say Solf J Kimblee, who dresses like a slave owner? Because Solf J Kimblee knows he's evil — he just doesn't care. Meanwhile, Shou Tucker actually thinks what he did to his wife, his dog, and his daughter, was morally justified. Few things are more frightening than evil that doesn't recognize itself.
Caster is the servant of a serial killer named Ryuunosuke Uryuu in Fate/Zero. Not only is he absolutely inclined to do his master's horrifying bidding, he also has truly unsettling motives of his own. In his previous life, he was devoted to Joan of Arc, a character based on the actual historical figure. When she was executed as a heretic, Caster gave up on trying to be a decent person.
He quickly went from small sins like squandering his money, to catastrophic sins like raping and murdering hundreds of little boys. As the servant of a serial killer, Caster delights in giving his victims glimpses of hope they might be saved, before murdering them in the most brutal ways imaginable. With such a harrowing resume, you'd think the dude would be more intimidating than creepy, but his character design, particularly his enormous, rolling eyes, put him over the edge and make your skin crawl.
Considering the fact Tokyo Ghoul is a show about monsters who eat human flesh, standing out as the chief creepazoid is no easy task. Tsukiyama doesn't just eat human flesh to survive, he revels in it. He appreciates different flavors, the way a sommelier appreciates a fine wine.
This almost sounds reasonable if you accept the premise he actually has to eat this stuff or he'll die. Since that's the case, why shouldn't he have a little fun with it? Reasonable... until you realize he hosts a spectacle in a gladiatorial stadium, with his victim being murdered in front of thousands of adoring fans. By the time you see him moaning into a handkerchief soaked in half-ghoul, half-human Ken Kaneki's blood, "reasonable" is completely out the window.
Sword Art Online's Nobuyuki Sugou is, to put it bluntly, a disgusting pervert. Engaged to the teenaged Asuna (he, of course, is a full-grown man), he's seen doing things like sniffing her hair while she's unconscious in a hospital bed, or licking the tears off her face after chaining her up against her will. She's in a hospital bed because he hacked into Sword Art Online servers in order to practice mind control techniques, naturally, and he ensured 300 test players, including Asuna, wouldn't be re-enter the real world after playing the game. So, dude put his fiance in a coma.
Kirito is so disgusted by how Sugou treats Asuna, whom he supposedly loves, he comes close to killing Sugou in the real world, but ends up leaving it to law enforcement. Considering how freakin' creepy Sugou is, you can hardly blame the kid for being tempted.