Rainbow Dragon [TAEV-EN006] Ghost Rare Champion Pack 7 you can discard up to

you can discard up to 2 cards to the Graveyard to select the same number of cards your opponent controls

but its original ATK becomes 0

you can inflict 500 damage to your opponent

the Fusion Material Monster that are listed on a "Gem-Knight" Fusion Monster Card

Rainbow Dragon [TAEV-EN006] Ghost Rare Champion Pack 7 you can discard up toSet: Tactical Evolution Card type: Effect Monster Rarity: Ghost Rare Attack: 4000 Defense: 0 This card cannot be Normal Summoned or Set. This card cannot be Special Summoned, except from your hand while you have 7 "Crystal Beast" cards with different names on the field or in your Graveyard. This card cannot activate its effects the turn it Special Summoned. Send all "Crystal Beast" monsters you control to the Graveyard; This cards gains 1000ATK for