I loved this. Tiny set, never lets up on the strangeness, deals with the occult alongside real-life horrors, and still packs in some great gore.
Using the tinniest of settings - one prison cell - the film stages a grand odyssey and one never tires of the setting.
As usual, I've got to complain that I don't think the trans character was handled in a manner consistent with the aspirations of trans-aware advocate-artists like myself.
All of the (four main and one temporary secondary) characters are complex and intriguing. For once, I'm not really that incensed at a "twist" ending, though I do think it was not appropriately foreshadowed and a montage of clips that were supposed to foreshadow the reveal shown right before the reveal is way too cliche and should have been cut.
Overall, the feeling of being utterly trapped with something so cryptic and powerful and surrounded by dangerous people is perfectly conveyed. I do wonder if there are modern prisons that are this shitty, though.