We took about 20% off of him but still my friend said that the damage was lower than the last time he fought it and was doing 3-4 times the amount of damage we were doing this time from the beginning of the fight. If he was always like that then @ 75 people would have been hitting him for 0 even when stoneskin wasn't up and 2 handers would have been doing the 3-4 damage a hit we were doing.