Mystic Swordsman LV6 Ultra Rare - Dark Revelation Volume 3 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 its ownerâ??s Deck instead of sending it to the Graveyard.