Here is the full list of all 22 Witch Hunt achievements.
Finish the game.
Kill 50 enemies in one playthrough.
Kill the witch.
Destroy the sacrificial tree.
Make 20 headshots in one playthrough.
Kill the beast.
Kill the night flier.
Attack the beast.
Attack enemy with lightning using thunder totem.
Don't get hurt by a whisperer.
Unlock and visit every location behind locked doors.
Unlock all skills in one playthrough.
Unlock 5 chests in one playthrough.
Find all save stones in the game.
Finish the game without dying.
Kill 3 deadblind in one playthrough.
Save a dog.
Find the weird looking skull.
Find the book of the dead.
Fire a cannon.
Finish game not using any silver crucifixes or watcher totems.
Finish game in perma mode.