Helm of the Forlorn Conqueror

Helm 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 Cowl
 * Mercurial Hood
 * Reinforced Sapphirium Faceguard
 * Reinforced Sapphirium Headguard
 * Reinforced Sapphirium Helmet
 * Shadowflame Hood

Source
This item drops from Nefarian in Blackwing Descent and Al'Akir in the Throne of the Four Winds on normal mode.