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