union arena code geass booster box Arena: The game play recreates the story Union Arena - Code Geass

S9 Star Birth is out of print with no announced reprint

Marketplace TCGplayer Sets Marketplace Cardmarket Sets Market Trend Price History Deck Usage & Meta Stats Public deck and tournament usage for Shaddoll Squamata

How to Play : Use Flare Strike as a strong opening hit, then switch Cinderace out to reset the cooldown

GSE Gold Secret Dark Advance X TRAP During either player's Main Phase or Battle Phase: Target 1 monster in your Graveyard with 2400 or more ATK and 1000 DEF

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