Seal Breaker Key

Seal Breaker Keys can be used to open the thrice-sealed Domination Sealed Cage and the Domination Chest Seal locking the Domination Sealed Chest at in Desmotaeron in the Maw.

Find one key inside Helgarde Supply Caches scattered about Desmotaeron. Kjellrun has one hanging on the wall at on The Harrower's Key Ring. Additionally, most Maldraxxi Defectors can drop one. Another can be found in the Feeder's Hand and Key which drops from Ylva. Four keys are required to unlock the Domination Sealed Cage and the Domination Sealed Chest inside of it.

All of this to loot the Nilganihmaht's Silver Ring for the Nilganihmaht Control Ring a mount unlocked in The Rift.