Storm the Vault (RIX #173)

Whenever one or more creatures you control deal combat damage to a player, create a Treasure token. (It’s an artifact with “{T}, Sacrifice this token: Add one mana of any color.”)

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.

{T}: Add {U} for each artifact you control.