Ragavan, Format Pilferer

Haste, flying, menace, hexproof
Whenever a creature deals combat damage to a
player, create that many Treasure tokens and
exile that many cards from the top of that
player's library. You may play lands and cast
spells from among the exiled cards for as long as
they remain exiled. If you cast a spell this way,
you may spend mana as though it were mana of
any color to cast it.