This quest is not available in game.
Bring some Fine Gold Thread, 2 Smoldering Coals, and a Soul Shard to Menara Voidrender in the Barrens.
I need only three things now, <name>, then we can finish your robe.
First, the fine gold thread Xizk is making for you. Return to him in Booty Bay and get it.
Second, bring me two smoldering coals from the fire elementals in the Arathi Highlands. If I recall correctly, they are to the west, near Thoradin's Wall.
Finally, a soul shard created by you.
After you have all the components, return here to the tower and I will complete the robe for you.