Hanzo, Scroll Hunter

Ninjutsu {2}{u} ({2}{u}, Return an unblocked
attacker you control to hand: Put this card onto
the battlefield from your hand tapped and attacking.)
When Hanzo deals combat damage
to an opponent, that player mills 3 cards, then
you may exile an instant or sorcery card from
that player's graveyard with converted mana cost
3 or less. Copy that spell. You may cast the copy
this turn without paying its mana cost.