Just wanted to mention that the amy that walks from the top of the pyramid down the ramp and then to the side is also a PHer. Hes the easiest of the 4 by far since he paths out and away by himself.
Pretty easy mob with my group. 2 90 mages, 90 bst, 2 healers. I had my lvl 83 monk with 26k HP be the puller. You need one for this mob. Pull him to the big hill SE from the temple. He spawned on the right of the 2 guys at the top of the temple and dropped Ambiguous Remnent of Devotion and a glowing nebulous fragment. Good luck!
we successfully spawned Mastelyn on the eastern most pyramid. there are 3 at the top. one inside, 2 outside. we got him from the right mob ( as you look at them). loc n615 x n1185 x p 185.