Mantle of the Forlorn Vanquisher

Mantle of the Forlorn Vanquisher is a tier 11 armor token. It can be exchanged at in Stormwind City or  in Orgrimmar for the following items:
 * Firelord's Mantle
 * Magma Plated Pauldrons
 * Magma Plated Shoulderguards
 * Stormrider's Mantle
 * Stormrider's Shoulderwraps
 * Stormrider's Spaulders
 * Wind Dancer's Spaulders

Source
This item drops from Cho'gall in the Bastion of Twilight on Normal mode.