- Female characters scream and shriek horribly as they are killed; most notably the female wizard, her voice often fades to a gurgle as her body is torn apart.
- Adria's betrayal, leading to Diablo ripping apart Leah's body, possessing her remains and reconstituting her form, and the rebirth of Diablo, the Lord of Terror himself, as the embodiment of all seven Great Evils in one being, the Prime Evil. And worse, Diablo wants to destroy the High Heavens themselves. Holy Shit does not even begin to describe it.
- The invasion of Heaven itself. The High Heavens are supposed to be a place full of holy and awesomeness, even if a lot of the angels are dicks. But when Diablo invades, you're treated to sights like angels being tortured, ugly demonic cysts that you have to destroy to continue and the place becoming more and more Hellish as you progress to the Crystal Arch. And as mentioned below, not even angels are immune to Diablo's evil!
- In the shoes of Lorath Nahr, this would've counted as one during Act V, when they're off to confront Adria. The Nephalem were so full of anger and vengeance that it just looks like they're willing to compromise the greater goal to find out Malthael's whereabouts just so they can kill Adria. When reminded that they need to get Malthael's location first, their answer is cold and as Lorath commented: "Well, that doesn't sound helpful...". This means we're facing with the very possibility as Tyrael feared at the end of the game: The prospect of humanity's savior being consumed with negative thoughts that they might doom others instead.
- Take a moment to listen to the music of Whimsyshire on headphones, full volume, in a dark room, and without looking at the game. note
- The Halls of Agony in general. These were King Leoric's old torture chambers, which saw plenty of use back when he was still alive and going insane due to Diablo's attempts to possess him and the evil whisperings of his Evil Chancellor Lazarus, claiming the lives of quite a lot of people, up to and including his own queen, who Lazarus manipulated Leoric into executing so he would be able to devote himself fully to turning Albrecht into a vessel for the Lord of Terror. And that was before Maghda and her coven decided to appropriate the place for their twisted rituals. What makes things even worse is reading his journal, which captures his descent from noble king to stark raving mad step by step. The Darkening was not a fun time to live through. To make things worse, in one of the later entries of this journal, Leoric states that he is aware of his madness, but powerless to stop his horrific actions.
- The massacre of Alcarnus in Act II, though not shown onscreen, showcases quite vividly just how evil Maghda and her Coven are. These are people whose primary means of fueling their magic (even illusions) involves Cold-Blooded Torture, and Maghda at this point is getting desperate.
- Ghom is a rare case of turning the Big Eater trope into Nightmare Fuel and Nausea Fuel. While you are fighting him, you can get your hands on his journal, which narrates how he forced his human prisoners into eating their own comrades, only to eat them himself after that.
- Listen very carefully when Diablo speaks. You can hear what sounds like screams echoing, just high enough to hear, but not louder than the background noise. It's surprisingly creepy. It's even worse assuming they are actual screams considering who they might be coming from. Poor Leah...
- The descriptions of some of the monsters are pure nightmare as well.
- One would expect the Tormented Stingers, for example, to be scorpion-like demons out of hell. But instead, these monsters are created by twisting the bodies of human sacrifices into these horrific forms.
- The Unburied are a hideous amalgamation of corpses flung into mass graves, animated by foul magic.
- Terror Demons are made from Diablo's nightmares and once drove a member of the Horadrim insane simply by appearing. Add that to the fact that their expertise are ambush attacks.
- The Skeletal Nightmares, which you fight near the end of the game in Act IV, are the ultimate fate of mortal sorcerers who summon and try to bind demons to their will, only to become enslaved to the very same demonic power. Deckard Cain notes in his tomes that they are the ultimate proof that there can be no peace between men and demons.
- Corrupted Angels in general, probably the perfect embodiment of just how bad things have gotten in Act IV.
- Malthael himself has become this. Originally he was The Archangel of Wisdom and the Leader of the Angiris Council but went mad sometime and now he has become the Angel of Death. I dare thee mortal.
- Cain's description of the Butcher is disturbing for a completely different reason: he describes the horrifying demonic Butchers. That's right, there are more of them.
- The Reaper of Souls intro has this with Malthael, specifically when, while he's butchering the Horadrim, we get to see his powers up close when he literally causes a Horadrim to wither and decay, ripping his screaming, struggling soul out of his body. Tyrael puts it best:...You should all... run.
- The first chunk of Act V, especially before you get to your first settlement. First you see a couple people running and screaming...par for the course, honestly, by now. Then you see a large group of people running, only to see their souls yanked from their bodies, turning them into Undead enemies to fight you. You progress, and are told about survivors in the church. You reach the church, only to see a jet of darkness burst from the doors. You hear pained screams for an instant, before they are rendered silent. Even as you play through Westmarch, you continue to see some...not all, but some of the soldiers get their souls pulled, turning them into Revenants, too.
- When you get close to the Soul Crucibles that you need to destroy, there are dead bodies everywhere, just piled up in the streets. And you have to walk over them.
- The Grand Maester's plan during The Templar Reckoning quest for Kormac. This bastard plans to implement the same horrendous initiation ritual that resulted in what happened to Kormac and Jondar and apply it on a grander scale, doing this to every citizen of Westmarch and beyond in order to make them Templars. And if the one being initiated has never committed any crimes? The Order will make up one just to have an excuse to torture the poor new recruit. It's little wonder that Kormac decides that the Maester, and the Order itself, need to end.
- Malthael's plan during Reaper of Souls. Tearing one Horadrim's soul out in front of Tyrael and eating it is disturbing. Seeing the Soul Crucibles in Westmarch, and the floor littered with bodies from the Reaper attack is horrifying. Then you learn from Tyrael and his fragment of the stolen Black Soulstone that Malthael is planning to use the soulstone to forcibly contain all demonic essence in the plane the Soulstone is in - and he's about to send it into Sanctuary. And human souls are half-demonic.]] By the time you reach him, he has a LOT of souls under his control, plus the Black Soulstone and its contents... And Malthael [[One-Winged Angel eats souls.
- The soul crucibles are nasty business themselves, seeing as they can rip the souls out of still-living mortals, leaving their flesh for use as Malthael's minions. You do manage to destroy all three (the one under Kasadya's control was incomplete, and crumbled when she died), but the implications of how many they claimed are still very nasty. You know it's fucked up when Myriam has difficulty tolerating their existence."Let's just say I need to see it destroyed with my own eyes if I am to ever sleep again."
- The Perilous Cave in Act V, a side dungeon that's teeming with giant maggots. Interacting with certain objects like corpses and loose stones will cause more maggots to drop from the ceiling. Oh, and there's the Maggot Broods, who spit out even more of them. Gross!
- The implications of Malthael's successful release of the Black Soulstone on Sanctuary. He tooled it to absorb all demons on the plane. And humans are all half demon. No one gives a clear answer to what this means, but everyone agrees that there is no way that it won't result in the death of every human on the plane.
- The following conversation with Eirena comes out of nowhere and isn't expanded upon either. The location at which she says it, such as King Leoric's mansion with its gruesome backstory, doesn't make things better either.Eirena: There are two boys playing over there. Can you see them?
Player: What do you mean? There is nothing there.
Eirena: *cheerily* Never mind. They must be dead.
- The literally-powered-by-hatred Demon Hunters already look scary enough with the Glowing Eyes of Doom that come with most helms, but The Shadow's Mask, part of The Shadow's Mantle set, hides their eyes in darkness, as befitting of the set's assassin motif. Each of the Nephalem are enough to scare the shit out of human opponents if the ingame cultists are any indication, but special emphasis should go to the Necromancer whose main powers consist of A: summoning up the dead the serve him/her, or B: ripping the opponent's blood or bones out of their body. Even their seemingly mundane ability to curse opponents is horrifying when you read the background lore and realize the Necromancer Curses are, in esscense Soul Rape:
There is no grave foul enough to suit this corpse. I will let it decompose in the sun until nothing remains but bone and sinew and shriveled skin.
- His journal entry involving Maghda's death shows just how ruthless he can truly be.
- Tyrael's Oh, Crap! realization at the ending of Reaper of Souls. The Nephalem has grown too powerful, yet still suspectible of being tempted to evil. And if they do not resist, humanity is doomed. You may want to start praying that they actually resist in the future!
- The Blood Cult of the Temple of the Firstborn from the new release for Adventure Mode are singularly nasty. Aside from their usual business of sacrificing others, they have a habit of turning people into living roach hatcheries, turn themselves into demons, and choose only the choicest of victims for their rituals. Knowing that they cannot take Nephalem in open combat, the cult steals upon them when they're asleep or unarmed before cutting open their veins for the blood they desire. And the guy running the show is Vidian, the Lord of Envy and one of Azmodan's surviving Sin Lieutenants, who presumably wants the power of the Nephalem for himself. The Temple itself is extremely creepy, full of rotten corpses hanging on the walls and roaches falling down from the ceiling in response to the corpses bursting, and basically combines the most disgusting parts about the Halls of Agony and the Perilious Cave.
- The sound cues of an impending Nemesis encounter. You hear a very low and ominous noise, your controller vibrates (if controller vibration is enabled), and then this unholy killer of yourself or someone else on your friends list spawns with a red mist surrounding them.
- Those giant... things in Cydaea's tower. It's never explained what they are but they are apparently trapped in endless torture, including having their flesh peeled off to use as material for the paths in the tower. One can only hope they were somehow destroyed when you kill Cydaea and destroy the Heart of Sin.
Nightmare Fuel / Diablo III