He pops at 846, 399... roams northwest to 1382, 676 then takes a sharp turn south / southwest where he wanders to about 1204, 745, then walks to 999, 661 and stops for a second. He then turns NW and walks to about 1217, 765, from where he re-traces his path that he took from his spawn point. Once at his spawn point, he follows the same path, but doesn't seem to want to stop at 999,661 again... instead he stop around 1110, 824 where he engages the guards. Confusing sounding, but mark the points on your map and the line should become clear... it will look mostly like an upside down check mark. Spawn time is between 11-12 minutes... closer to 12.
I believe this is erroneous information. Mobs will drop both incandessence and luminessence of the same slot but only of one slot (warped, fractured, phased, etc.), with the exception of some instance mobs such as Borskar.