For Yshtola, it came down to a mix of popularity of the character as well as being a spellcaster, her story and character development offered a wide range of abilities and moments to pull from to lead the deck
Sure, there are a few problems here and there, but the flavor delivered by Wizards of the Coast is, as per usual, mostly stellar
Crystal Fragments // Summon: Alexander (Borderless) - Final Fantasy (Foil Near Mint) You want to be informed when the price of Crystal Fragments // Summon: Alexander (Borderless) - Final Fantasy (Foil Near Mint) reaches a certain value
Functionally, what this effect says is that if you can attack with The Lord Master of Hell, and you have 40 or more cards in your graveyard that are neither creatures nor lands, you win the game
This all culminates in an ending where Yuna's whistling to try and desperately reach out to a Tidus who's not there, which in turn results in a post-credits scene where, well, play the game for yourself