It seems that any mob with "scorned" in its title is a ph for this named. I have gotten Bishop to spawn from 6 out of the 7 "scorned" spawn points.
I would agree with the previous poster about removing any form of levitation on all of your characters, mercs, and pets. Leaving levitation on is asking for trouble.
Finally, I recommend setting up camp in the first room you come to that has scorned mobs in it. Kill those two mobs, leaving time between the kills, then proceed to move into and clear the last 2 rooms with scorned mobs. In the middle room with 3 scorned mobs, each of those can be killed without aggroing the others if you invis and move your group close to them before engaging. Hint: Kill the first one you see upon entering the room, then the one to your immediate right, then the far one all by itself near the opening to the final room. After killing the last 2 scorned mobs in the final room (the one with the bunkbeds) just invis and head back to wait for respawns in the first room.
Bishop himself is pretty easy for a named. GL :)
Kharlos Silvertongue
90 warrior
Echelon