Volatile Abomination

Prowess
Volatile Abomination's power is equal to the number of instant and sorcery cards in all graveyards.
When Volatile Abomination attacks, you may exile target instant or sorcery card in a graveyard with converted mana cost equal to or less than Volatile Abomination's power. You may cast a copy of that card without paying its mana cost until end of turn.