union arena code geass booster box Arena: Having a serial number card that caused a buzz during vol.1 is being used for vol.2 as well! Union Arena - Code Geass

S9 Star Birth is out of print with no announced reprint

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

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

C Common Dragon Dowser X EARTH Level 4 [ WyrmEffect ] ATK 1500 DEF 1500 When this card is destroyed by battle and sent to the Graveyard, or when this card you control is destroyed by an opponent's card effect and sent to your Graveyard: You can Special Summon 1 EARTH Pendulum Monster from your Deck in Defense Position, but destroy it during the End Phase

place it on the top of the Deck