The Warlord's Treatise

The Warlord's Treatise is a quest item only lootable by players on the quest WANTED: The Warlord's Treatise. The quest is a random daily heroic quest from Wind Trader Zhareem in Lower City.

Source
This item drops from Warlord Kalithresh in Steam Vaults on heroic mode for those on the quest WANTED: The Warlord's Treatise.