I'm not sure about all the tasks this guy has but the task for the Shadowknights includes an item from which the zone it's found in does not exist. The Opalescent Two-Handed Sword is a drop from the Reef of Coirnav which doesn't exist in Emu's at this time.
Edit: Looking through all the other tasks, most of the weapons themselves are from elemental PoP content, except for the SK weapon, but the imbued item most all require with the weapon take a Mephit Blood drop of some type. These Mephit Bloods are drops from the Reef of Coirnav as well and therefore unavailable.