Storm the Vault
 
 
 Whenever one or more creatures you control deal combat damage to a player, create a colorless Treasure artifact token with "Tap, 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.
 
 
Vault of Catlacan
 
 
(Transforms from Storm the Vault.)
Tap: Add one mana of any color to your mana pool.
Tap: Add U to your mana pool for each artifact you control.