Speak of the devil.

On the day of his scheduled execution, a convicted serial killer gets a psychiatric evaluation during which he claims he is a demon, and further claims that before their time is over, the psychiatrist will commit three murders of his own.
In Nefarious, consciousness is carried by the dead — a plane of “prison possession”. The story fights on E8/E9/E10 of the E0–E14 reality ladder, compressing religion, possession, law, morality.
Films fighting at the same level of reality, about the same things.
Other films that move a human interior onto the same kind of thing.
The Unborn (2009)consciousness in the dead · spirit-haunted home
The Amityville Horror (2005)consciousness in the dead · haunted house
Paranormal Activity: Next of Kin (2021)consciousness in the dead · demon‑possessed farm
Ghostbusters II (1989)consciousness in the dead · ghostly city
Vampires (1998)consciousness in the dead · undead hunt
A Return to Salem's Lot (1987)consciousness in the dead · vampire enclaveThe same preoccupations carried by a different kind of thing — grief told through the dead, an animal, a machine.
The Conjuring: The Devil Made Me Do It (2021)consciousness in monsters · law, possession
Prey for the Devil (2022)consciousness in monsters · possession, religion
Annabelle Comes Home (2019)consciousness in objects · possession, religion
Fallen (1998)consciousness carried elsewhere · possession, religion
The Hidden (1987)consciousness in animals · law, possession
The Jungle Book (2016)consciousness in animals · law