The simple answer is you cant tank him anywhere EXCEPT in the auras ... to get rid of his buff put three people one in each arua just dont have them stay there long ...some people use bards I know ... once all three auras have been occupied the buff will drop and his regen will not be 10000000 hp a tick ... then go to town on him ... collect loot
We never tank him in an aura anymore. If you dont leash him he does not seem to develope the insane regen.