XX-Saber Fulhelmknight

Card text

When an opponent's monster declares an attack: You can target the attacking monster; negate that attack. This effect can only be used once while this card is face-up on the field. If this card destroys an opponent's Defense Position monster by battle: You can target 1 Level 4 or lower "X-Saber" monster in your Graveyard; Special Summon it.