The Shadow Tower Vault is a type of chest that appears after killing a Shadow TitanShadow Tower. It requires a Shadow, Moon or Eclipse Key to open (the key used depending on the difficulty of the Shadow Tower). Players can also use keys from higher difficulties to open lower tier Shadow Tower Vaults with the Eclipse variant being the universal key.
It drops different loot depending on the the difficulty level (Uber 3-9). In addition to unique drops, it always grants a large quantity of Relic or higher rarity equipment.
For items such as Boss Trophies and Mounts, they drop from their respective boss chest and an increased chance between difficulties (x2 for Hard and x10 for Ultra).