Take the goblin body to the vestibule entrance at the bottom of the Obelisk.
Click on the vestibule door.
Only the person who clicks on the door gets the update if more than one person has the quest.
When you enter the zone you have the choice of going left or straight. Go left there are two 44^^ enraged shades down the stairs, kill them they have been known to add through the walls, so this is just saving you from possible adds later. The door at the end of that passage is locked for now.
Go back and take the straight passage, when you come up to the room there will be 2 groups of lvl 50 mobs, either 4 with no arrows or 2 ^. Be careful they will add from down in the pit. There are also lvl 35-42 solo mobs, 3 of them around the room but they are non-aggro.
Clear the room. Now this is where it gets boring, as far as we can figure there is no way to spawn the named quick, just keep killing off the placeholders until he pops. He is a lvl 50^^ named Medium of Hykor. He has 2 adds, as well. He has a single target nuke, for up to somewhere in the 2k range, it is divine dmg and hits about every 40 sec to 1 min.
After you kill the Medium, the door at the end of the other passage unlocks. Go in and place your goblin on one of the six tables in the room. If you are not a full group, or all of you are not on this quest step, you can receive more goblins by examining a bag in a slot on the wall. Place a goblin on each of the six tables.
When a goblin is on each table a shadowedman seed will spawn behind the table (non-aggro). After 2 min the seed will "die" and the goblin will come to life as his new host. The goblins are 38-42^^ and have 2 spirit eviscerators that are not linked. When you kill that goblin another shadowedman seed will spawn behind another table and the 2 min cycle repeats again. When you kill the last of the 6 goblins a lvl 49^^ Heroic, Malisient, will spawn with 2 adds. The named has an AE knock-back attack.