how many cards in yugioh hand Top 10 Bounce (Return to Hand) "Yu-Gi-Oh!" Hand | Yu-Gi-Oh! Wiki |

So if you have Energy on Flutter Mane through Professor Sadas Vitality , or you dont plan on attacking with a specific Pokemon, you can move an Energy from it to make sure you can attack with another Pokemon

Overall I expect rotation to be a much bigger factor in Standard changing than Bloomburrows release

And likely in two steps, by skipping the new shiny Pokmon at first and only focusing on all regular new Pokmon and their forms

In their heyday, they inspired such unprecedented moves as the first balance-motivated ban in Vintage, a card being preemptively banned in Commander prior to release, and an entire mechanic being significantly reworked via official errata