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