It's the fact that she doubles your creature death triggers
Nostalgia + Innovation: The set pairs classic characters like Ethan, Cynthia, and Giovanni with new mechanics like Trainers Pokmon, appealing to both collectors and players
It's part Massacre Wurm, part Withengar Unbound, and it's an altogether cool addition to the set, even with clear multiplayer text tacked onto a Standard-legal card
Jace might not be the best Planeswalker in the set, but he remains a threat, nonetheless.
Part of a cycle that features the almost-as-broken Gaea's Cradle and somehow the hilariously unbroken Shivan Gorge, Tolarian Academy taps to make a mana for each artifact you control, which led to decks that would dump their entire hand of cheap artifacts, make a ton of mana by tapping and maybe untapping Tolarian Academy, and then use big card-draw spells like Windfall and Stroke of Genius to refill before eventually milling the opponent out with Stroke of Genius, potentially all on Turn 1
Just keep in mind that if you double attack triggers with Isshin or Wulfgar that only one trigger will resolve if they already sacrifice the permanent for the first trigger
