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