Yeah I don't receive any dmg from aggy either. Tank takes the damage from aggy and wyrm tamers and druid stands behind tank out of aggy range.I don't think we are fighting the same aggy. He does no chaos damage to me.
Maybe it's because I stand just to the left of his fire breath.
Snorri sweeping blow is rough though.
I have my fortitude at almost 1600 and sometimes still get 1 hit dead with 4.1k hp...not usually but on occassionn.