Breastplate of the Wayward Conqueror

Breastplate of the Wayward Conqueror is a tier 8 armor token. It can be exchanged in Dalaran for the following items:
 * Conqueror's Aegis Battleplate
 * Conqueror's Aegis Breastplate
 * Conqueror's Aegis Tunic
 * Conqueror's Raiments of Sanctification
 * Conqueror's Robe of Sanctification
 * Conqueror's Deathbringer Robe

Source
This item can be found inside the Cache of Winter after defeating Hodir in the 25-man version of Ulduar.

This item is also sold by the following vendors for :
 * in Dalaran
 * in Dalaran