Mantle of the Forlorn Conqueror

Mantle of the Forlorn Conqueror was a tier 11 armor token. Prior to patch 6.0.2, it could be exchanged at in Stormwind City or  in Orgrimmar for the following items:
 * Mercurial Mantle
 * Mercurial Shoulderwraps
 * Reinforced Sapphirium Mantle
 * Reinforced Sapphirium Pauldrons
 * Reinforced Sapphirium Shoulderguards
 * Shadowflame Mantle

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