Silent-Blade Oni
{3}{U}{U}{B}{B}
Creature -- Demon Ninja
6/5
Ninjutsu {4}{U}{B} ({4}{U}{B}, Return an unblocked attacker you control to hand: Put ~this~ onto the battlefield from your hand tapped and attacking.)
Whenever ~this~ deals combat damage to a player, look at that player's hand. You may cast a spell from among those cards without paying its mana cost.