Mystic Swordsman LV6 (RDS-EN008) - Rise of Destiny Unlimited

If you Normal Summon this card, you must place it in face-down Defense Position. If this card attacks a face-down Defense Position monster, destroy the monster immediately with this card's effect without flipping it face-up or applying damage calculation. You can return the monster destroyed with this effect to the top of your opponent's Deck instead of sending it to the Graveyard.