Brux, Rouen's First Born

Flying, indestructible, hexproof
Cumulative upkeep-Put a -1/-1 counter on Brux, Rouen's First Born.
Pay 2 Life: Look at the top two cards of target opponent's library, exile one of them face down, then put the other on the bottom of that library. For as long as that card remains exiled, you may look at it, you may cast it, and you may spend mana as though it were mana of any type to cast it.