Rolynd, Kleptomaniac

When Rolynd, Kleptomaniac enters the
battlefield, look at the top 3 cards of your
opponent's library. You may exile one of them
face-down. You may look at it for as long as it
remains exiled. You may play the exiled card. If
the exiled card is a spell, you may spend mana as
though it were any color to cast that spell.
"I like to consider stealing more of an art than a
crime, and if that is really the case, you can call me
the Picasso of this craft."