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