Algernon Cadwallader

Hexproof, Unblockable
Whenever Algernon Cadwallader deals combat damage to a player or planeswalker, you may pay {b}. If you do, reveal the top three cards of your library. You may reveal a nonpermanent card from among them and put it into your hand. Put the rest of the cards into your graveyard.
{w}{u}{b}: When y