Here is the full list of all 13 Shadows: Heretic Kingdoms achievements.
Acquire the Reaper sword.
Reach level 10.
Defeat the Scorpion King.
Successfully escape Thole.
Defeat the Aphotic Spider Queen and her minions.
Unlock the Ishkai Sniper soul.
Max out one of your skills with any puppet.
Earn second level
Avoid fighting the Werewolf Berserkers.
Complete Book One.
Reach level 20.
Reach level 30.
Have Zaar fulfill his most fervent desire.