Ice Cauldron

{x},{t}: You may exile a nonland card from your
hand. You may cast that card for as long as
it remains exiled. Put a charge counter on Ice
Cauldron and note the type and amount of mana
spent to pay this activation cost. Activate only if
there are no charge counters on Ice Cauldron.
{t}, Remove a charge counter from Ice Cauldron:
Add Ice Cauldron's last noted type and amount
of mana. Spend this mana only to cast the last
card exiled with Ice Cauldron.