You can Ritual Summon this card with "Magikey - Maphteah". Gains ATK equal to the number of different Attributes in your GY x 300. You can only use each of the following effects of "Magikey Cannon - Garesvet" once per turn. When your opponent activates the effect of a monster with the same Attribute as a monster in your GY, while you control this card Ritual Summoned using monsters with 2 or more different Attributes (Quick Effect): You can negate the activation, and if you do, destroy that card. If this Ritual Summoned card is sent to the GY: You can add 1 "Magikey" monster from your Deck to your hand.