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Nightmare Fuel: Black Butler
Deals with the devil? Sounds like it should be creepy!
In Chapter 31 when Ciel and Sebastian are at Baron Kelvin's mansion and are having dinner. The "circus" show he has a few children put on isn't all that scary... Until we see a little girl on the tightrope fall and we're treated to a panel of her leg and a nice splat complete with blood squirts. Then we see two other children drag off her headless corpse, leaving a lovely, bloody trail behind. Or how about the child who was a lion tamer that's eaten right on stage? The fact that Baron Kelvin is laughing and applauding makes it all the more frightening. Then he acts surprised that Ciel doesn't like the "show" he had the untrained children put on special for him. It was a pretty disturbing chapter
In the first episode of the anime, a businessman comes to Ciel's house for dinner. At some point, he excuses himself and goes to answer a phonecall. Apparently, he was trying to cheat Ciel or something, of course, our favourite demon butler hears this and decides to make him pay by driving the man insane with hallucinitions to the point where Sebastian locked him in an oven. the calmness of his voice is chilling...
Ciel's flashbacks. A crazed cult leader stabbing a child in front of you? Horrific. How about a doctor who uses children's bones in his prosthetics stabbing a child in front of you the same way the cult leader did? Really horrific. Ciel got physically sick when he saw the doctor do this.
Drossel Keinz living dolls are terrifying for people with Dollphobia. But also the fact that he himself is a doll is quite the Fuel itself. But the worst thing for Dollphobic is the puppet of Drossels "Master".
For the few episodes he's in, Drossel is loaded with creepy. He decapitates someone on screen, uses jewelry to pick out his victims, and always has that Creepy Monotone along with the Ironic Nursery Rhyme. One noteable bit of terror is when he's talking with Elizabeth on picking a gift for Ciel before he comes to his decision, you get a close up of his face with Lizzy reflected in his eyes.
Black Butler II also has its fair share of horror, but the one scene that tops everything occurs in episode 10. It begins with Hannah talking to Ciel and saying that she has something to show him. Perfectly pleasant, right? Then her mouth opens unnaturally wide to reveal this black abyss where the inside of a human mouth would be. The eye she stole from Alois Trancy is rooted in the back of her throat, and since Ciel's soul has been partially fused with Alois's at this point, he's basically staring at himself from inside her. Hannah watches calmly while Ciel suffers a severe nervous breakdown. Also counts as Paranoia Fuel, since up to this point the episode made you believe that they were really going to hit it off as master and servant.
That bit where Claude is brainwashing Ciel into thinking he's Alois. Rewriting his past.
complete with nightmarish computer glitch-like transition between Angela's face and Ash's face. Oh man. And this troper thought only the When They Cry series could get that creepy...
Ciel's Laughing Mad moment at the end of the Circus arc in the manga is terrifying, especially considering how reserved he generally tries to be. After a massive PTSD attack in Kelvin's mansion and arguably crossing the Moral Event Horizon by burning down the entire mansion with uncountable innocent kidnapped children inside, discovering it was All for Nothing makes him... laugh, and laugh, and laugh, and babble about how humans are revolting and desperate and "even more demonic than a demon", and how he's the same. And as the ribbon off his hat is stolen by the wind, you remember that this is a thirteen-year-old kid....