D/D/D Supersight King Zero Maxwell

Before damage calculation, if this card attacks an opponent's Defense Position monster: You can change the DEF of that opponent's monster to 0 until the end of the Damage Step. If this card attacks a Defense Position monster, inflict piercing battle damage. You take no battle damage from battles involving this card.

You can target 1 face-up monster on the field; its DEF becomes 0 until the end of this turn (even if this card leaves the field). You can only use this effect of "D/D/D Supersight King Zero Maxwell" once per turn.