As per Nightmare Fuel policy, all spoilers are unmarked!
- FRIGGING ALL FOR ONE. An immortal crime lord and remorseless Serial Killer, he has been terrorizing Japan for two centuries, and the slow reveal of his past brings to light many atrocities. To make it worse, he is charming and makes valid points about the corrupt state of society and its hero-obsessed culture. He has a deep love for his family and some form of moral code, which makes his inhumanity far more glaring and horrifying.
Conversations of a Cryptid
- Izuku's realization of Tsubasa's horrific fate. Tsubasa may have been a bully, but Izuku didn't want him mutilated and tortured beyond all recognition. Izuku only realizes it when a forum user emails him a newspaper article of Tsubasa's disappearance and a Noumu's similar wings. And to make matters worse, evidence points to Tsubasa's own grandfather being one of the parties responsible!
- Endeavor's spousal abuse, marital rape, unlawful marriage, and child abuse are all known by many reporters. But he is so powerful and so protected by the government that he's untouchable and no one can stop him.
- All for One's blase reaction when Izuku points out All Might's justified anger at him killing his mentor. He doesn't flat care about Nana Shimura beyond the fact she was a One for All user and wouldn't have found at all noteworthy if it wasn't for All Might.
- Shiragaki's attempted home invasion. Had Inko left any later or arrived any earlier Shiragaki and Kurogiri might have held her hostage. And there's Shiragaki unsettling reaction to the revelation that All for One had no involvement in Izuku's life. Shiragaki scratches and scratches himself to the point of bleeding.
- All for One's origins. Once one of many vigilantes that arose to protect their own from Anti-Quirk backlash, a bad call by the government to illegalize unauthorized Quirk use birthed the League of Villains and lead All for One terrorizing Japan for two centuries!
- Izuku's kidnapping. Izuku's abduction occurred when he was distracted for a single moment, and he is missing for a week with no one able to find him. The Sludge Villain from the first arc kidnapped him and horrifically tortured Izuku to the point that he's brain dead by the time All for One rescues him.
- All for One's correctional officers let down their guard for one moment, believing that they have sedated him. All for One uses this opportunity to slaughter the entire prison staff, murder his psychiatrist, and break out of prison without breaking a sweat.
- Eri can finally use her powers safely! Yay! Too bad, she unintentionally restores All for One to his former glory!
- Izuku's circumstances at the end. Izuku is kidnapped and powerless against All for One, who deliberately took a power canceling quirk to contain Izuku. To make matters worse since All for One is Izuku's father, Izuku's allies are helpless to save him without destroying Izuku's life.
Kidnapping of a Cryptid
- The reveal that Recovery Girl has a long history of medical malpractice has never gone to medical school, practices without a medical license and has had many patients die under her care is horrifying! To think someone who's supposed to be the funny White Mage has been operating on Izuku and Toshinori despite not being a real doctor. And Yuuei was willing to protect her and continue to get away with if it wasn't for Inko and All for One exposing her.
- Inko's life. She was orphaned and managed to get out of the foster system and get a great career for herself. She meets a charismatic and handsome man, who's rich and enthralled with her. They both fall in love and get married, Inko unknowingly marrying a remorseless Serial Killer. The fact that he is also the man who murdered her mother makes it even if more worst.
- Worse yet, the reason she was given her job in that company in the first place was so that one day, All for One could manipulate All Might into causing her death, making the hero inadvertently kill the remaining child of his beloved master. It was only pure luck that Inko unknowingly caused Hisashi to fall in love with her and thus escaping her original-planned fate.
- Izuku's threat that internal organs count as small objects to Inko's telekinesis, implying a sweet woman can be very deadly if pushed.
- All for One's public assault of Bakugou. All for One has despised Bakugou for a long time and had many of Bakugou's former friends disappeared and tortured due to their connection to him and their bullying of Izuku. All for One relishes in hurting a powerless Bakugou and gives him a brutal Breaking Speech detailing how he will mutilate Bakugou if he is cruel to Izuku again while holding Bakugou by the throat in the air the entire time.
- If All for One is right, then One for All steals it's wielder's will to live when it's passed on to a new wielder. Quirks within families tend to be similar in some ways, and his own is parasitic. Furthermore, Toshinori is the only wielder of One for All who didn't commit Suicide by Cop against All for One after passing on their Quirk.
- Bakugou is alone in the hospital when Hisashi Midoriya show up out of nowhere when no one is watching. Bakugou can't even scream for help because his throat is still injured from when Hisashi strangled him. Had Hisashi been less interested in making Bakugou suffer, he would have been dead.
- Their society is so unstable with the rampant super crime, discrimination and government corruption that it only takes one rightly placed article to have everything fall apart. Even if the Japanese government deserved it, everything has devolved to anarchy and riots. Nothing Is the Same Anymore
- A minor one comes from Mineta's scheme with Tsuyu to get himself suspended. Despite him blatantly groping Tsuyu, none of the teachers except Aizawa and All Might try to stop him. The rest either ignore or outright encourage one of their charges sexually assaulting another student.
- The Reveal of just how corrupt the government and society in general is. David Demir is harmless, though schizophrenic, Thai man who's Quirk gives him metal claws. When his father died, he forgot his medication and his neighbors called the police who in turn called the local heroes. David was beaten and thrown into an asylum where he was drugged up and forgotten for three years. According to him, there were several non-Japanese there as well, many of whom couldn't speak the language and whose only crime was having a scary/evil Quirk, such as a woman with spikes growing out of her back. Meanwhile, people like Shu (whose Quirk makes him a Cthulhumanoid) struggle to find jobs because of their appearance.