Bosses
Urivar
Initiate boss in Nahantu. Hoard opens with a Lair Key.
Where and how
His lair is in the Fields of Judgement, near Kichuk in Nahantu. 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.