His placeholder is the shadowmane that spawns by the knocked over column lying on the ground. He is a solo pull if you camp him from the hill by his spawn point. I camped him for about 6 cycles (he or the PH popped every 10 - 12 minutes or so) and he popped on 4 of the 6 cycles. Dropped the pendant 3 of the four times. The Avenger 1 time.
Very fast camp.