There aren't actually any rulings about how the player must perform the shuffle, meaning that they could theoretically conceal their shuffling completely and turn your opponent's blocking into a complete guessing game as opposed to trying to follow the shuffle around which might have been the intention of the card
The BREAKpoint Greninja has free retreat, while the XY Greninja can do another 30 damage with its (regular sized) Water Shuriken, so including both in this deck will give you options
Ravnica was light on the novelty of new mechanics
Previously, Magics Universes Beyond crossovers have taken place in Middle-earth with The Lord of the Rings: Tales of Middle-earth, the martial arts-filled world of Street Fighter, and even the undead nightmare of The Walking Dead
The data shows that lots of people play Standard, especially on MTG Arena, so it comes around to one of the more common answers for too many questions, money: It costs too much to play Standard in paper
