Spirit of the Darkness

Vigilance, Trample
Whenever Spirit of the Darkness attacks, exile
the top card of each player's library. You draw
a number of cards equal to the number of total
converted mana cost of cards exiled this way
this turn. You lose that much life.
{t}: Choose target card in exile. You may cast
that card this turn and you may spend mana as
though it were mana of any type to cast it.