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