Here is the full list of all 10 Witch Halloween achievements.
The Act of faith ending achieved
12 ghosts exorcised
The first ghost appease the ghost
12 ghosts tamed
Kill the inquisitor
The "Love and peace" ending achieved
The "Blaze" ending achieved
The "The ghosts' toy" ending achieved
"There are no ghosts" ending achieved
The "And what about the ghosts?" ending achieved