Scornfang Noble

Exploit
When Scornfang Noble exploits a creature, exile
the top card of target opponent's library. For as
long as that card remains exiled, you may cast it
and you may spend mana as though it were mana
of any type to cast it.
{4}{b}, Pay 4 life: Return Scornfang Noble from
your graveyard to the battlefield tapped.