Being a Genre Throwback to the era of practical creature effects, it's inevitable that there will be some horrifying visuals.
Spoilers are off, as per wiki rules. You have been warned.
- For starters, the mutant creatures. They're some of the most horrifying and grotesque monsters put to screen since The Thing (1982).
- The father in general. While he can't be blamed for hating the cult that murdered his family, he blows it way out of proportion and gets way too violent with people who don't really deserve it.
- Daniel, James, the father and the son find a room in the sub-basement (which doesn't even exist) that resembles a slaughterhouse with the carcasses hanging everywhere. Then they see a monster trying to kill itself by skewering its head on an exposed length of rebar, to no avail. The father aptly sums it up as the creature turns its mutilated head towards them and the rest of the monsters attack.Father: We're in Hell!
- Powell casually peeling off his skin while giving Allison a disturbing Breaking Lecture about how her baby died: it was strangled by the umbilical cord.
- Daniel walking in on Beverly driving a pair of scissors through a patient's eye, then turning her head towards him, revealing her peeled face.
- The birth of Maggie's mutated child. Powell "blesses" Maggie by placing his daughter's soul inside her child ... who promptly emerges from her womb, tearing her apart from the inside. What comes forth is an abomination far worse than anything previously seen in the movie, and it cries just like a human baby.
- An additional bit of horror is that after the "birth", Maggie's corpse is shown being DRAGGED behind the abomination due to still being attached through a nest of tentacles!
- The implications behind the existence of the Void. It isn't heavenly, nor is it exactly hellish. It's simply a barren, rocky wasteland watched over by an Eldritch Abomination, and it's all but stated that this is what awaits everyone after death.
- There's also the fact that when Daniel and Allison are reunited there, they're alone. If this really is where all souls go after death, there should be billions of others, but nobody else seems to be in their vicinity, not even Powell despite both him and Daniel having entered the Void together. So, although you apparently can reunite with your loved one(s), you'll be alone with them, in an endless wasteland without a hint of civilization or comfort, under the ominous eyes of unknowable entities, for the rest of eternity.
