This card can only be used when there is a face up Dark Mathematician on your side of the field the field. When there is no Dark Mathematician on your side of the field, destroy this card. Once per turn, when your opponent decares an attack, role any 2 dice with six sides. Add up the numbers and multiply them by 2 within 5 seconds from when they stop rolling . If you succeed, negate the attack. If you fail, the monster's attack can not be used to activate any of your other mathematical cards this turn.