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