Currently I am playing as a necromancer.
Being frail and not expecting his beam to go the other way, I got hit in the final phase and died almost instantly.
My skelebro’s however were quite buffed and quickly finished him off on their own.
When i pressed revive (after he went down due to a distraction), the quest finished and I respawned in his arena with the ability to proceed the main story asif I won.
This happened yesterday.
i am not completely sure if the version was 0.9i or 0.9i2 by that point.