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