Bosses
Lord Zir
Initiate boss in the Fractured Peaks. Hoard opens with a Lair Key.
Where and how
His lair is in the Darkened Way, east of Kyovashad in the Fractured Peaks. You can now travel straight to it from the map. The hoard takes one Lair Key, and killing him also gives a Greater Lair Key.
Unique pool
Mythic drops from this hoard come from this pool. See Lair bosses for how mythics work.