Ominous Vault

The Ominous Vault is a less common variant of the Vault, both of which are found in Trial Chambers and can only be opened with either a Trial Key or Ominous Trial Key depending on their variant. Ominous vaults can only be used once per player.

Ominous Vaults usually generate higher up than Regular Vaults, and are embedded in the chamber's walls. Beebom^[1] has a full guide on finding and opening Ominous Vaults.

The Ominous Vault may notably drop an Enchanted Book of Breach, Density or Wind Burst, Flow Armor Trim, Flow Banner Pattern, Heavy Core, Ominous Bottle III-V and a Wind Charge. Both Regular and Ominous Vaults drop three to six sets of loot, though there is a chance (6.8% on Java and 7.3% on Bedrock) for each set to drop nothing. Destructoid^[2] lists the full Ominous Vault loot tables for Java and Bedrock Edition.

It takes around 250 seconds to break an Ominous Vault using any tool, and it will never drop even with the Silk Touch enchantment.