Bounty: Thorfen is a bounty task in Pillars of Eternity.
Synopsis
Thorfen, a high priest of Eothas, has been accused of desecrating gravestones, and then of killing Crucible Knights sent to stop him. There's a bounty on his head.
Walkthrough
Speak to Warden Fyrgen in the restored Warden's Lodge in Caed Nua and accept this bounty task. He'll only offer it to you after you have completed all of his tier-1 bounty missions:
Once you have the task, travel to Esternwood, and approach the graveyard in the North-West of the map.
Thorfen (a 10th level priest of Eothas) and his party hide out there, and attack as soon as they see you:
Defeat them, and pick up his head from the bodies (1962 xp, loot: 6300+ consisting of fine and exceptional weapons/armor, about 1000 cash and Coat of Ill Payment).
Bring the head back to Warden Fyrgen at Caed Nua to collect your reward (2250 , 3924 xp, therefore 5886 total experience).
(given xp numbers were for a party of 6 at level 11, so base values are probably a higher number, need to be verified)