Spoilers ahead.

Hereditary (2018)

When you think it cannot get any worse, it does. And it is even worse that you could ever imagine. The whole family is falling apart after the pole incident. The pole incident, probably the biggest shock in any movie in years. No one predicted that. No one COULD predict that. Die are cast and there is no stopping it. The control is not in their hands. And then the most unexpected happens. Everything is lost. There is no going back. One psyche damaging blow after another. Unrecoverable error occurred and it is beyond repair. People die, or worse. Absolute demonic suicidal dread. And the simple “click” sound is stronger scare than any cheap and predictable jump scare you have ever seen. Mind shattering despair escalating at an overwhelming rate. Immolation. Body in the attic. And then Paimon himself manifests.

The Witch (2015)

VVitch

When the main heroine questions her sanity after all that happened to her and goes into the shed, and Lucifer himself starts talking to her “Wouldst thou like the taste of butter?” — goosebumps are inevitable. Also, witches gain their power from the fat of small children, so think about the “butter” scene.

Notice the black mushrooms growing on the crops. Ergot used to cause psychedelic hallucinations when ingested, which had exactly the same symptoms as demon possession.

REC (2007)

In one of the last scenes her camera guy records is the Spanish reporter being chased by her firefighter friend who just turned, and by chance finds the right key to open the door just in time. She then enters the room she thinks is the safest, not knowing it is exactly the opposite of that. Core of all primordial evil.

It follows (2014)

It follows you everywhere. It will not stop until you are dead. Invisible “It” on the beach, chasing you. Your friends do not see it and think you are crazy. You are safely at home, your friend opens the door, and It is there, behind her. It will never stop.

Black Mirror / Playtest (2016)

Imagine a neural network learning your darkest and deepest fears, implanted into your brain. Once it learns what you fear the most, it will keep you through augmented reality in the deepest fears you have. For the main hero it is becoming his father and mother. Having Alzheimer’s disease and forgetting who you are. But wait, imagine a reality inside a reality inside a reality, from which you cannot escape consciously or know you are in one. You will die here. But first you will forget who you are.