Figured we should start a thread to discuss strategy for this quest or at the least, to share info on it. Here is the info I have atm:

Dagnor the Beserk

Rating: 125 Kwellen Beserker

HP: 65K approximately

Known Attacks: Beserker Barrage-roughly 3k to 4k of mind damage

Boil Blood-roughly 2k of spirit damage

Known Weaknesses: Fire and Nature seem to hit for damage

Respawn: Less than 10 hours.

Please feel free to add more info. I'll post as I gain more knowledge.