As a Nightmare Fuel page, all spoilers on this page are unmarked as per policy. You Have Been Warned.
- Although it sets the tone of the series, the first scene of episode 1 wherein a student is publicly hung in front of the entire school all for stealing a One-Star uniform as Satsuki spouts her fascist rhetoric is honestly terrifying, even for the moments clearly being Played for Laughs. Considering how rare actual deaths are in the show? It's actually very gruesome.
- How Senketsu's transformation looks from the outside
◊. First he begins to bloat up creating what seems to be teeth around the openings (sleeves, neck, bottom of the shirt, upside of the skirt, frills of the skirt). Then he bloats up even bigger with Ryuko visible in his mouth. Then he seems to jam his mouth shut with Ryuko's head and hands sticking out between his "teeth". Then he presses himself together vertical and then horizontal still with Ryuko visible. Finally he forms into her combat outfit, his teeth disappearing. All while blood is spitting out. While it doesn't seem to be all too painful, Ryuko looks visibly exhausted. Both members of the student council witnessing it are a bit disturbed. The transformation sequence after Ryuko fully "accepts" Senketsu looks considerably less painful until Ryuko's berserker rage, that is. - Nui Harime. A sweet-looking, peppy young woman who just so happens to be a psychotic assassin and The Dragon to Ragyo Kiryuin. Not to mention, she's the person who killed Ryuko's father, something she admits to Ryuko's face with sickening glee. Nui is horrifyingly competent at fighting even without a Kamui, and enjoys psychologically (and sometimes physically) tormenting her opponents, all without dropping her happy-go-lucky attitude.
- In contrast to the over-the-top dynamic animation style of the rest of the show, Nui is barely animated at all when she moves. Instead, she merely slides in and out of frame, utilizing (and even weaponizing) Limited Animation and Toon Physics to her advantage. It manages to capture the Uncanny Valley in a truly frightening way by having Nui defy the laws of the very medium she exists within - almost like she shouldn't exist in the world of the show.
- The end of Episode 11, where Ryuko learns that Nui killed her dad. After a stunned silence, she explodes with rage in a rather horrifying animated sequence which shows a close-up at her face, screaming with pure rage at her father's murderer. Wide Eyes and Shrunken Irises combined with the potent fury on her face, and the episode ends with a freeze-frame of it. This Nightmare Face makes Ryuko look outright inhuman... which could be a fitting prelude to what happens in the immediate episode after.
- We're treated to the same scene at the beginning of Episode 12, kicking back off where we left when Ryuko flew into a frenzy.
- The whole of Episode 12 after Ryuko, consumed by fury and already in her Roaring Rampage of Revenge, causes Senketsu to lose control, and ultimately mutates both him and Ryuko into this hideous, mindless, howling monstrosity that looks more like something out of The Thing or a David Cronenberg work than anything else. In some shots, it's clear that Ryuko's neck isn't connected to her spine any more, and the "horns" coming out of the top of her head are actually her bottom teeth cutting through her skull. Then she gets the Cooldown Hug, and everything's better! Except instead of a quick, sparkling change back; we see in black-on-red silhouette as her body very slowly twists itself back into a proper shape, with more groaning and sobs of pain, and the very unsubtle popping and snapping of joints and ligaments as they are bent back in place.
- Ragyo Kiryuin is an absolute nightmare. Everything about her is horrifying - the way she treats everyone (even her own children) as disposable tools, her disgusting sexual abuse of her own daughter Satsuki, the fact that she's The Quisling who gleefully sells out humanity to become batteries/food for the Life Fibers just because of her twisted brand of social darwinism, the fact that she just won't die.
- Flashbacks show how much of a vile sociopath she truly is. After only marrying Soichiro Kiryuin for his intellect, the two experimented on their children. After their first child, Satsuki, didn't bond with Life Fibers due to being too old (at just one year of age), they tried it again on their second child literally as soon as she left Ragyo's womb. This time, Ryuko seemingly dies from the experiment, but while Soichiro is devastated with what happened, Ragyo merely complains that something with "her genes" is so weak before disposing of the body like common trash and walking away like nothing happened. It was so vile that Soichiro betrayed his horrific wife, saved the child (who he would name Ryuko), and spent his whole life working to destroy the Life Fibers and everything Ragyo stood for.
- The shot of sewing needles, cables and Life Fibers implanted into baby Ryuko's back is both nauseating and horrifying, especially to viewers who are Afraid of Needles.
- The fate of those that are overpowered by Kamui◊ is to be made into clothing and consumed.
- The sudden Nightmare Face Nui gives Mako in episode 22,◊ as well as every one after that. Hell, her entire Villainous Breakdown after Ryuko chops off her arms is terrifying - seeing Nui's sanity completely deteriorate as she starts shrieking in pain and rage about how she's going to kill Ryuko and everyone she loves is not a pretty sight to behold, cathartic as it may be.
- Her expressions in the helicopter are especially terrifying, as she's practically frothing at the mouth with hatred while the stumps of her arms spray blood on Hououmaru's expressionless face. However, when Hououmaru warns her about Ragyo's possible reactions, Nui's face becomes terrifyingly blank for a brief moment. No matter how much Nui may hate Ryuko, she fears disobeying Ragyo infinitely more.
- Nui is just as dangerous as always in the finale, but then things escalate. Ragyo notices that the Primordial Life Fiber is weakening and orders Nui to sacrifice herself for its sake. In most other series, you might expect The Dragon to refuse, considering their own life more important than that of their boss or the goals they've been working towards this whole time... but not Nui. She gleefully does exactly what Ragyo tells her and, smiling and giggling the whole time, cuts her own head off (to everyone's understandable horror) and is absorbed into the Primordial Life Fiber, which briefly turns into even more of an abomination, now one that looks like it has Nui's face.
