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