The Iron Bank of Braavos

You may cast spells from your hand without paying
their mana costs. Whenever you cast a spell this way,
place X credit counters on The Iron Bank of Braavos
where X is equal to that spell's mana cost. At the beginning of your upkeep you must remove all
credit counters by paying {1} for each. For each
counter that is not removed you lose 2 life and each opponent you control creates a treasure token. Then remove those counters.
"The Iron Bank is always glad to be of service."
—Tycho Nesto