Inkubus

This movie tells the story of a skeleton crew working the final shift at a soon to be demolished police station. The night takes a gruesome turn when the demon, Inkubus, calmly walks into the station holding the severed head of a murdered girl.

The cops quickly become pawns in Inkubus' crowning achievement of murder, gore, and mayhem. They ultimately realize it's his world, they only die in it.