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