Nightmare Fuel / Live A Hero

• The Kaibutsu in general. They're interstellar, interdimensional monsters that manifest from seemingly no where and require eating people from reality to fully form. And even after fully forming, they keep eating.
  • People that are eaten by the Kaibutsu and are failed to be rescued not only die but any memories and evidence they ever existed are erased. This means those that are eaten are effectively erased from existence. Chapter 1 shows a temporary version of the memory erasure when the children that Kyoichi saved forget him after he's eaten. Later story makes this increasingly scarier: in the Christmas event, when Kaibutsu are spread out all over Nessen's ryokan/resort, a random person runs into a conference room, panicking about someone near them going missing. When people try to calm this person down and ask for more details, the person then forgets who they were talking about and why they were so freaked out in the first place. Most people in the conference chalk it up to a random freakout, but Subaru notes that this is the fourth time this has happened, which means that at least four people were eaten by Kaibutsu and barely anyone batted an eye because everything about them was wiped from everyone's minds.

• The ending of Chapter 1 has quite a few:
  • Ryekie ends up impaled in the stomach after jumping in front of a child when the nearly dead Kaibutsu turns its body into a thorn, intending to kill the spectating kid. The last we see of the tiger for the chapter is him collapsing while bleeding heavily.
  • The mysterious man that was watching the Protagonist during the chapter's climax says he can't wait to see the Protagonist be tormented by their own power, before he sends them to "oblivion" himself.

• Chapter 2 escalates things:
  • It's revealed that when Mokdai was young and lived in the slums, a giant fusion-type Kaibutsu wreaked havoc and ate all of his friends in front of him: since he had the potential to be a hero, he was the only one who remembered them. Even though it was defeated, many heroes died that day, and the incident is still remembered.
  • At the start of the chapter, Exio is talking to a mob whose powers as an Observer had apparently just awoken. The player isn't shown exactly what their full exchange is, but it seems that Exio told him how to attract Kaibutsu to a location, as that mob later goes on to attract dozens of Kaibutsu to attack his former workplace; however, the situation rapidly spirals out of his control, as far more Kaibutsu than he anticipated show up and form into a giant fusion-type Kaibutsu that the main heroes have to stop. As they all plan how to fight it, they all acknowledge that this kind of Kaibutsu is very dangerous, and it's very likely that some of them will die fighting it.
  • After the incident, when the player is going home, the mob finds them, recognizing them as the Operator for the heroes on the broadcast, defeating the Kaibutsu he drew in. He declares that his plan was to be the one to save the day, to be the Operator for the heroes who came in to defeat the Kaibutsu, but the player ruined it, and in his delirious rage, he pulls a knife on the player character and tries to stab them. Then a Kaibutsu appears out of nowhere and eats him, followed by a black hole opening in the ground beneath the Kaibutsu and it vanishing into it. Exio then steps out of the shadows to express his disappointment with the mob's inability to do anything right, then tells the player that he can control Kaibutsu and that they are now the only two people who remember the mob, as he just erased him from existence; he says all of this completely calmly, totally unbothered by the horror of the action he just committed.