So all it took to kill him was to tear him limb from limb like that? How come nobody has ever tried to simply behead him before?
Personally I'm not convinced he is dead.
In his own words, his immortality is quite amazing. There is in my mind a distinct possibility that if you were to behead him, the head would remain alive - Black Knight style. Awakened seem far more durable than that, and Joko was the uber-Awakened. Lesser Awakaned have been brought back to undeath after getting all messed up and thought dead, too.
Which of course raises the posibility that he might still be alive inside of Aurene in some kind of horrible, horrible vore-inspired fever nightmare....!
Please Anet give us a hide Chest Armour-option. Tattoo-clad Norns everywhere beg of you.