There are a few cards that really care about having chocobos out, and Gysahl Greens is the cheapest, simplest way to get one
The story here is that you are accepting hunting missions, fighting and slaying increasingly epic monsters (known as Marks), until you are ready to battle the biggest and baddest monster of all: Yiazmat
A serialized card includes the total number of cards in that run plus a unique number to tell you where in that run the card falls
The card's art and ink color are both unique, as all other Elsa cards have been Amethyst so far
Then there's Abuela Alma, who enables you to go digging through your deck for a Madrigal character, which further cements the predictability of the deck key in a tournament setting
The scanner works really well (almost as good as Manabox for Magic) and the Cardmarket integration is also really solid