Ok so with this being a hot zone here, I have spent more time just hunting mobs for exp. Here are some details on the Massive Deep Orc:
I made a map here Map for the Massive Deep Orc
As you can see it is near the zoneline to Undershore. You just enter the zone with invis and levitate and make your way to the right side wall. Climb up that and float over to the first broken bridge in the zone. If you see High Pries Preyan, dont just say hello until your grp is ready. He is not such an ez mob to solo if you are not ready. He or his PH, a illsalin grunt, spawn about once every 2-4 hours so that bend in the walkway is a fairly safe camp area.
From the bend in the walkway, pull and split the 2-1-2 orcs to get to the PH/Massive orc. The PH is always a higher lvl mob than the surrounding deep orcs and they are all social. Meaning all orcs will run at 20% health and so need snaring unless you are fighting 2 of them at once. This includes Massive orc.
Since I was basically soloing, I could only do enough dps to keep the 6 orcs and maybe 1-2 Illsalin dead before respawn. Each time Preyan spawned I needed to rest afterward from the long hard fight. Preyan or his PH rarely were up ever. They just are not a concern unless you are at that camp for several hours.
The massive orc is no harder than his PH. In ways he is the same difficulty as his PH Deep Orc. Does not enrage, Does run at low health, Does not Flurry, Is slowable/crippleable, can be snared, summons. (all the deep orcs summon)
Normal loot on Massive is the cape, 1 Greater SS rune, and a couple misc tradeskill or vendor drops.
Rare is the Atk Aug and Rare is the Glowing rune.