Rainbow Dragon (CT04-EN005) - 2007 Collectors Tin Limited

This card cannot be Normal Summoned or Set. This card cannot be Special Summoned except when there are at least 7 different "Crystal Beast" cards with different names on the field or in your Graveyard. This card cannot activate its effects the turn it is Special Summoned.
•Send all "Crystal Beast" monsters you control to the Graveyard; this card gains 1000 ATK for each card sent. You can activate this effect during either player's turn.
•You can remove from play all "Crystal Beast" Monster Cards in your Graveyard to return all cards on the field to their owners' Decks.