Was able to get him as a single pull, no tricks. Working from Underquarry zone in, go due west. The circular area on your map is where he spawns. As you enter the circular area, clear mobs to your right. You will need crowd control or the ability to split or handle 2 mobs at a time.
He spawns on a platform on the central column, PH is an Autarchian model.
As you work your way right, his platform comes into view on your left as you hug the wall. Pull to here, no adds. He sees invis, as do some of the Autarchian Lords and Komatites on your way to him