Gem-Knight Master Diamond is a Secret Rare Fusion Monster card from Yu-Gi-Oh! (Hidden Arsenal 7: Knight of Stars, HA07). Current market price: $0.13.
Secret Rare
Hidden Arsenal 7: Knight of Stars (HA07)
Card Text
3 "Gem-Knight" monsters
Must first be Fusion Summoned. This card gains 100 ATK for each "Gem-" monster in your Graveyard. Once per turn: You can banish 1 Level 7 or lower "Gem-Knight" Fusion Monster from your Graveyard; until the End Phase, this card's name becomes that monster's, and replace this effect with that monster's original effects.
