Storm the Vault - Vault of Catlacan
Legendary Enchantment - Legendary Land       (2UR)
Whenever one or more creatures you control deal combat damage to a player, create a colorless Treasure artifact token with "[T], Sacrifice this artifact: Add one mana of any color to your mana pool."
At the beginning of your end step, if you control five or more artifacts, transform Storm the Vault.
(Transforms from Storm the Vault.)
[T]: Add one mana of any color to your mana pool.
[T]: Add U to your mana pool for each artifact you control.