Frostfire

Crystallize {w}{u}(When you successfully cast this
spell from your hand, exile it and create a Crystal
artifact token with "{w}{u}, Sacrifice this permanent:
You may cast Frostfire from exile for {0} until end
of turn.")
Frostfire deals 4 damage to target creature. If you
cast Frostfire from exile, tap another target
creature. It doesn't untap as normal during its controller's next untap step.