Pearls of Warding can be used to earn higher valued rewards from replaying Vaults.
Upon entering the Vault—after converting the required Pearls of Warding— you can be blessed by Zoltun’s Warding, a special layered blessing which grants access to riches within the Vaults. Zoltun’s Warding diminishes stack by stack if you manage to fall prey to the various Hazards scattered throughout the Vaults.
If you manage to keep Zoltun’s Warding intact after defeating the Vault Boss, you’ll unlock a Wardwoven Chest, which has a higher chance of granting Legendary items. Using Pearls of Warding can increase the risk by exchanging them for extra stacks of Zoltun’s Warding at the Vault entrance—succeed, and your reward will increase as well.
At World Tier III, Nightmare Vaults unlock. Vault Sigils will drop alongside typical Nightmare Dungeon Sigils, or they can be crafted which will require Pearls of Warding to create. These Vaults function similar to Nightmare Dungeons—however they will have deadly Constructs and Hazards scattered throughout, and the Wardwoven Chests for the savvy wanderer.
Malphas’ seeks to unleash deadly Constructs upon Sanctuary, pouring from the underground Vault to terrorize the innocents and sinful alike. Dismantle deadly traps, destroy Lesser and Elite Constructs to earn Shattered Stone. Dispatching Elite Constructs grants Pearls of Warding which can be used to earn higher valued rewards from replaying Vaults. Negate the Arcane Tremor by defeating the Vault’s mighty Herald Construct, securing a tenuous peace to the denizens above.