Here is the full list of all 27 Demonheart: Hunters achievements.
Sabotage a quest for the Church of Ravage.
Complete all Church of Ravage quests faithfully.
Sell 30 Healing Salves.
Sell someone's skull.
Kiss Brash.
Kiss Ari.
Kiss the demonspawn.
Kiss Sinallion.
Sleep with Thayn.
Obtain Poison Attack skill.
Obtain Poison Attack II.
Obtain Poison Attack III.
Rescue your demonspawn ally.
Rescue Brash.
Board a ship.
Find Mr. Edgardo.
Release the trapped demonspawn.
Reach Raze's Inferno.
Reach Thayn's Inferno.
Choose the young demonspawn as your ally.
Choose the adult demonspawn as your ally.
Reach maximum Good alignment with Bright.
Reach maximum Tactful alignment with Bright.
Reach maximum Evil alignment with Bright.
Reach maximum Defiant alignment with Bright.
Side with humanity.
Side with Thayn.