- How does it feel like to be Impaled with Extreme Prejudice? Well, thanks to Mage Association's order, we get to first-hand witness of 49 elite mages already impaled by Kazıklı Bey, visibly alive and twitching while barely able to scream. And now you know why Vlad III is notoriously known by the epithet "Vlad the Impaler".
- Vlad's powers themselves are pretty terrifying once you think about them. Within his territory, he can make his stakes sprout from anywhere he wants even inside his opponents' bodies.
- His transformation into Dracula just takes his horrifying nature to its logical conclusion. First off, he's visibly writhing and screaming in pain as his body warps in entirely new ways from rearranging limbs to growing wings out of his back. Then his face turns into something right out of a monster horror movie while he speaks with the Voice of the Legion. And then he starts murdering and turning people into vampire minions. It says something when Vlad himself states he would never use this power of his own free will.
- Spartacus, A.K.A. Berserker of Red, isn't just creepy, he's absolutely insane. He's a giant of a man dressed in a Stripperific fashion, and he always has a Slasher Smile, especially when the thought of killing "oppressors" crosses his mind. In fact that's the only thing on his mind. As a Berserker, he naturally has Mad Enhancement giving him a boost, but it does little to hinder his ability to talk coherently, and that's the most unnerving thing about him. If he thinks you're an oppressor, he won't stop until he gleefully kills you.
- His Noble Phantasm, Crying Warmonger, makes him become more powerful the more he gets injured. Eventually, all that power makes him mutate into a hideous blob with multiple heads.
- Jack the Ripper, despite being incarnated as a young girl, is no less brutal in her murdering of her victims. Post-mortem autopsies on her victims revealed that they were gruesomely cut into pieces and had their hearts gouged out. By the next episode, Reika offered a mage's heart as a dish.
- We get to see the wonderful sight of Jack gleefully torturing a poor guy to the point of begging her to kill him. She wanted info on how to get past the castle's security, and gave that guy hell right before ripping his heart out. This is probably how she killed most of her victims.
- Her invasion of the castle is pretty terrifying. The mist blanketing the area doesn't just conceal her presence, it also emits an acidic effect that will kill anyone who breathes it in.
- Despite encountering her before, Chiron and Fiore realize that they can't remember what she looks like or what her abilities were. That means Jack has a unique ability that erases all traces of her true identity, abilities, and even appearance. Right after she lives the castle, Sieg and Fiore, the only ones who saw her that day, can't remember what she was like.
- When Reika dies after saving her from Atalanta's arrows, she shoots Jack again and assume she's dead... until Jack gets back up while pulling an Exorcist Head move before her body explodes the fog from her body. Her death stare with glowing red eyes says it all.
- For a Servant or any Heroic Spirit who has a shred of nobility or innocence in their mind... getting summoned by Celenike will count as this. First of all, it doesn't matter who you are, but she will treat you as an utter slave and once in a day, you get taken to her private dungeon to be lecherously licked. Go against her orders and she will put you through torture devices and torture you until she's satisfied. If you claim your morals, she will balk that you are just a copy of the original spirit, thus not at all heroic and will be nothing more than a Servant that must always obey her... and she will use her Command Spells, no matter how inefficient, just to make sure you violate your code of justice and just to see your virtuous image and self-esteem sink into despair for her own pleasure. This woman is bar none one of the worst Masters that a Servant could have. Astolfo was lucky that Mordred beheaded Celenike before things could get any worse and that Sieg was around to make him his new Master... that's right, just when you thought someone killing said Master would free you from slavery, you'll be destined to DIE unless you got a new potential Master ready to make contract.
- Avicebron (Caster of Black) wants to recreate Paradise with his Golem. Well, that sounds jolly... except to complete the Golem, he needs someone that has been very close to him, and that happens to be his own Master and pupil, Roche, who gets thrown into the core of that Golem, screaming and calling out Avicebron on his actions as the Golem absorbed him. The Golem itself is a gigantic abomination that could give Spartacus a run for his money and any man-like creature (real men or homunculus) it touched will be forcibly absorbed to him. And the more it fights, the more it gets more powerful from strength, toughness to agility, to the point that unless it's taken down in a swift moment, that kind of monster would be completely invincible and nothing would stop it to recreate the world into a Paradise without humans.
- Episode 18 is this AND tearjerker. It is also the beginning of a downward spiral of the usually calm and collected Atalanta that continued in further episodes. After witnessing Jack being purified, which brought her back memories about her being abandoned as a child, she slowly slips into madness, first constantly ranting against Jeanne with Berserker Tears on and constantly putting bulged out eyes because of it. The sight of Jeanne became her Berserk Button that she became fixated in killing Jeanne to avenge the children and refused cooperation with her allies that even Achilles, who would usually try to befriend her casually, became unnerved at her, and afterwards she became some sort of Screaming Warrior that screams "RULEEERRR!!!" angrily whenever Jeanne is around. This eventually culminates into her discarding her heroic side to activate her forbidden Noble Phantasm, Agrius Metamorphosis, that turned her into an extremely feral Berserker-like beast just for a chance to kill Jeanne and exact vengeance. To witness Atalanta's slow transformation into a raging beast can be rather terrifying.
- It's not given a name in Fate/Apocrypha, but Fate/Grand Order outright calls this form "Atalanta Alter."
- The extent of Shakespeare's abilities is downright nightmarish. This guy has a kicker for 'tragic' stories without regards of what his designated actors would feel and his answer for that, AKA his Noble Phantasm, First Folio? Mind Rape his victims with a 'theatrical play' where someone from the actor's mind was acting really out of character just to break their spirit. We only saw early tidbits of it when he inflicted that to Frankenstein, enough that she freaked out and had to be restrained with a Command Spell, but the full effect is when he did that on Jeanne, when it caused Jeanne to witness the noble version of Gilles de Rais not only bring a severed head of Sieg, his face also transforms into his evil Caster version from Fate/Zero, complete with bulging fish eyes. Shakespeare is definitely not the guy you want for telling children bedtime stories!
- Semiramis, being an Ur-Example of poisoners, is a definitive nightmare to fight against when she's at her lair in Hanging Gardens. She can change anything to contain any kinds of poison/venom that she wanted just to break you apart inside out without her touching you. If that wasn't enough, she could also summon legendary venomous beasts to strike on you on top of all those. Dying due to poison/venom overdose is horrifying, and Semiramis can do just that with a snap of a finger.
Nightmare Fuel / Fate/Apocrypha
Fate/Apocrypha had averted most of the Nightmare Fuel from the Fate/stay night.... but offers a flavor of Nightmare Fuel on its own.