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

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

place it on the top of the Deck