Magic: the Gathering - Datenbank

Bottomless Vault enters the battlefield tapped. You may choose not to untap Bottomless Vault during your untap step. At the beginning of your upkeep, if Bottomless Vault is tapped, put a storage counter on it. [T], Remove any number of storage counters from Bottomless Vault: Add [B] to your mana pool for each storage counter removed this way.