Naoko, Pursuing Samurai

Bushido 2 (Whenever this creature blocks or becomes blocked, it gets +2/+2 until end of turn.)

Whenever Naoko, Pursuing Samurai deals
combat damage to a player, choose one —
• Exile the top card of that player's library.
• Until end of turn, you may cast a card
exiled with Naoko without paying its mana
cost.