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.
Buy the Lighthouse.
Play on the Hospital map
Buy the Pub.
Successfully joined the "family."
Purchase Two Crucifix
Exorcise the ghost 5 times.
Correctly identify the ghost 3 times.
Read EMF Level 5.
Play on the Cyclone Street map.
Take Two Photos Of The Ghost.
Correctly identify the ghost once.
Exorcise the ghost once.
Die once.
Play on the Abandoned House map.