This item is a quest reward from the following quests:
Change in Patch 2.3Edit
The Attuned Dampener will be changed in Patch 2.3 to the spec listed above. Prior to Patch 2.3, the item did only 525 to 675 Arcane damage, and only referred to being attuned "to a specific being" (Araj the Summoner). In the Patch 2.3 PTR, the damage was increased significantly, and the comment now specifically refers to Araj (presumably because Chromie now knows when it's most useful).