Noticed that he could be attacked, but would not attack back other than a single Riposte, may have done it more, but as a necromancer I decided not to attack after being hit in the 800s by the first. He didn't riposte once on pet, has the hp of a level 62-64 in the Pre-Elemental Planes. Has not respawned on server since the first time I killed him.
got bored and killed him the other day since no one seems to know what hes for. i was able to attack him, but he didnt fight back at all except for one riposte. even if i pushed him away from the center of the bridge, he would just walk back while i beat on him. didnt seem to have too many hp, and definitely no sort of extraordinary regen. didnt get any exp for killing him obviously, and corpse disappeared instantly on death.