Chestguard of the Lost Vanquisher

Chestguard of the Lost Vanquisher is a tier 7 armor token. It can be exchanged in Dalaran for the following items:

Source
This item can be found inside the Four Horsemen Chest after defeating the Four Horsemen in the 10-man version of Naxxramas. It can also drop from Gluth, or it can also be purchased from Arcanist Ivrenne or Magistrix Lambriesse for.