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