Let us break it down for you
The deck's main MTG commander Tidus is all about moving counters around, apparently based on the Sphere Grid level up system, and so it's not surprising Yuna plays around with counters too
I decided it would be a good idea to expand it into a full article to help newcomers quickly grasp the mechanics
This Magic: The GatheringFINAL FANTASY Starter Kit contains 2 ready-to-play 60-card decks, 2 deck boxes to store them in, 1 Magic play guide booklet, 4 double-sided tokens (2 with each deck), 2 double-sided reference cards to aid you as you play (Turn Order/Attacking & Blocking), and two Magic: The Gathering Arena code cards to unlock both decks for two people to play online
Wizards of the Coast (WotC) unveiled the three Secret Lair drops for Magic: The Gathering FINAL FANTASY today
Emerald/Ruby is a control-style deck that has some strong advantages in multiplayer and does a great job stalling the Steel/Sapphire starter deck in particular