Room 1 shoot everything that moves and take the gate facing upward

Room 2 shoot the overseer then take the gate (overseer do a lot of damage)

Room 3 shoot everything that moves (overseer do a lot of damage)

room 4 (final room) shoot overseer, loot $$$$ (overseer do a lot of damage)

site is doable with ishtar speed tanking, carefully manage traversal when approaching overseer
final room overseer require about 700DPS to kill efficiently

All overseer may drop true sansha mods and gives T2 salvage. 
Final boss drop overseer effect, centum A-type mods and phantasm BPC