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