Vault of the Wardens: Borrowing Without Asking

Objectives
Recover a Containment Crystal from the Vault of the Wardens on Mythic difficulty.
 * Containment Crystal
 * Suggested players: 5

Description
The elusive Wardens run an immense secret prison facility deep underneath the mountains of Azsuna housing all manner of terrible creatures.

Perhaps... 'used to run' is more accurate.

This presents us with a unique opportunity. The wardens used powerful containment crystals to encase each prisoner in their cell. If any of them still remain intact, we could use one to safely contain the Heart's power.

They certainly won't be needing them.

Rewards
You will receive:

Progress
Any luck?

Completion
Excellent. This will work quite well.

Gains

 * 16,450 XP