When an opponent's monster declares an attack, or your opponent activates a monster effect (Quick Effect): You can Special Summon this card from your hand. You can only use this effect of "Kuriboh - Multiply!" once per turn. Once per turn, if an opponent's monster attacks, during damage calculation, OR, when your opponent activates a monster effect on the field (Quick Effect): You can add to your hand, or Special Summon, 1 "Dark Magician" or 1 monster with 300 ATK/200 DEF from your Deck or GY, then you can change that opponent's monster's ATK to 0.
