Spinal, Eternal Warrior

{u}{b}, {t}: Counter target instant or sorcery spell
that targets you or a permanent you control. If
that spell was countered this way, exile it with a
skull counter on it. Activate this ability only once
each turn. (Spells exiled this way can't have more
than one skull counter.)
{2}{u}{g}, {ut}: You may cast up to one spell in exile
with a skull counter without paying its mana cost.
If you do, remove the skull counter from that
spell.