This Telmiran mob is found one floor down from the top of the temple (in the lower section; The Collector being in the upper). It is in the northeast corner of the northeast room.
Known spawn location: -880, 905, +780 (4th level of the fortress)
We've seen the Litho pop in 3 different locations then listed in loc's. In the first small room to the right on the third floor there are 3 static litho's. The two in the corners of this room are ph's. Just outside that room are two statics to the right and three to the left. I've seen Litho Bakann at two of the three spots in that bunch. It would make logical sense that any litho model in that area is a ph.
He spawned from "a lithographer" in another spot in that room. I'm guessing any of the "a lithographer" are ph's. Dropped the Lithographer's Earring and Damascite Encrusted Brachial Clay.
Only "trick" to this one is it is very spell resistant like the subjugator, but also seems to change what element it's vulnerable to every couple or few ticks (with an emote).
Bring your melee dps again since the fight is annoying for casters.