Y'shtola has a few things going on mechanically, and they all combine to make her a powerful Commander
Dark Clouds Gather Exit The Golden Stables and turn right, going up the slope and into the elevator
Then, Madam Mim can bounce him safely back into your hand, setting up a vicious cycle that, if it isn't stopped, can give you a huge lore lead
When it comes to protecting your board, few cards do the job as well as this one (though unlike Teferi's Protection, it gives no such security to your life total)
On play, she's a serious threat, providing card draw, giving you more ink, and she stacks with other copies of Cinderella, Dream Come True
With the Final Fantasy 7 cards in particular, you can see the entire story from start to finish with impactful moments shown in beautiful new art