Demonic Accountancy

Whenever you discard one or more cards, exile
an equal number of cards from the top of target
opponent's library.
- You may exile a card from you hand to cast one
of those cards. You may use mana of any color
when you do so. Your life changes by the
converted mana cost of the spell exiled minus
that of the one cast.
- Cards that let you cast a spell they exiled can
also be used to cast the spells this card has.
"It WILL all add up right." -Voluptura, Accountess.