Soul-bound

If this card enters your hand, shuffle it into your library.
If this card becomes the target of a spell that
would destroy it, instead exile it and the creature
it's attached to.
Enchanted creature has, "whenever this creature
deals combat damage to another creature, exile
that creature, you may look at and cast it for as
long as it remains exiled and you may spend
mana as though it were mana of any color to cast
it."