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