At each of the four rooms, there is a small hallway, relatively safe to fight on, no adds if you stay to the middle of each hallway. Easy pulls and fairly easy kills
Stand in one corner to left or right of him. Hit mob in corner and he will agro and the other mob 90 degrees from him will too. Mez 2 mobs and kill him.
Or, as a Bard I can mez 2 mobs at the bottom of the stairs, run back into the room east of him and fade. Then snare him and fade again till he's alone. It's tough but doable.
dont have location but in the west end of zone there are 4 rooms 1 south 1 north 1 east 1 west this one spawns in the west room on the far west wall is 3 mobs near the wall the one in the middle is ph