Here is the full list of all 19 Demonologist achievements.
Play on the Bedlam map
Exorcise the ghost in the Bedlam
Play on the Kurosawa House map
Successfully joined the "family."
Buy the Pub.
Buy the Lighthouse.
Play on the Hospital map
Play on the Cyclone Street map.
Purchase Two Crucifix
Exorcise the ghost 5 times.
Revive your friend with a Tarot Card.
Correctly identify the ghost 3 times.
Exorcise the ghost once.
Take Two Photos Of The Ghost.
Read EMF Level 5.
Play on the Abandoned House map.
Die once.
Correctly identify the ghost once.