union arena code geass booster box Arena: There are 4 levels of rarity Code Geass - Lelouch Booster

IIRC in Yugioh there is only a certain number of Blue-Eyes (from the show?), so you could put a rule on the card 'there may only be X Blue-Eyes on the battlefield at any time', Star Wars CCG used to have permanents that you could have 2 or 3 copies of in play, in addition to stuff you could only have 1 of, the concept would work fine here too, only this could care about both players' boards

place it on the top of the Deck

Pokmon TCG: Celebrations' Rarest Cards - Xerneas EX Originally part of the XY Base Set , Xerneas EX was one of the Pokmon to first introduce Fairy-type energy to the TCG

The only time the characteristics of the back face really matter is when the permanent is on the battlefield with its back face up

Agent of the Iron Throne Aristocrat decks benefit from the inclusion of Agent of the Iron Throne