Group wiped on him today. I was the last one standing. I decided to stick a nuke on him just to get a general idea of his HPs.
A 9554dd instantly took him from 100% to 97%. Expect him to be in the 325k hp range, not counting in-combat regen and his dreaded lifetap.
Be prepared for a long fight, that's for sure. A steady total of 350dps coming from our group could not take his health down any before he regenned it back.
His melee is not that bad. Can quad for a max of 842, but he is fully slowable. He puts out an average 200dps once slowed.
Oh, and also... he can be split from his guards. Bring enough dps along to handle his regen, and killing this version of him isn't that bad, just extremely long.



Cloak of Daggers
Earring of Twisted Visions
Hooded Shroud
Nightmare Rift
Recurved Wormwood Bow