Jyrasil, the Unresting

Double strike, vigilance, menace, haste
You may cast Jyrasil, the Unresting from your
graveyard.
Whenever a creature that was dealt damage by
Jyrasil, the Unresting this turn would die, you
may exile that card. For as long as it remains
exiled, you may cast it and you may spend mana
as though it were any color to cast it.