"Ultimate Crystal", known as "Ultimate Gem God" (
In the TCG, none of the members of this archetype have the archetype as part of their name. This is because, for over ten years, this archetype's only two members were "Rainbow Dragon" and "Rainbow Dark Dragon", and all support for the archetype referenced those two specific cards by name. When "Rainbow Overdragon", the first new member of this archetype, was released in the TCG, the original two members and "Overdragon" were given an archetype condition stating that they were always treated as "Ultimate Crystal" monsters. All support for the archetype subsequently received errata appropriately (except "Rainbow Path", but since it only searches monsters in the Main Deck, it does not interact with "Overdragon" anyway, so it did not require errata).