Killed him same day I killed Magiken and Psiospore. He is no more difficult than either of these mobs, cons light blue to 68 BST. I would put his level at very close to theirs, no more than 56-57.
This fellow can be single pulled across the river towards the tunnel to Undershore. Just need to wait for the pather to move out of agro range to pull or harmony/pacify the pather to pull. He, or the PH, respawns approx every 20mins and for me appeared about twice in two hours (may have been unlucky) though he dropped first time around his wrist item and second time around the legs. He is really no different to the other mobs, of the same type, with comparable damage output to the others.
The location below (neg 199 pos 1436) is accurate.