Ender Vaults were features that were added on September 25, 2015. They were since removed from SaicoPvP, coming back as a monthly-crate system on July 10, 2017.
Ender Vaults used to 72-slot storage systems that could be bought on the online store, or found in crates. Once placed, they could not be broken, and the only way to raid them was to use a Lockpick on them. Lockpicks had a chance of working, and if they did you could choose a few slots and hope the loot in the vault displays there. Lockpicks could be found in crates or bought on the store.