LOL.
She deserved her buff between base and YnK, and PYukari is certainly not overpowered. If she manages to start getting serious, it's the opponent's fault most of the time. Even then, she still has an average defense that can easily be broken. Not to mention that scarves (or other speed boosts) and priority are things that do exist.
Oh, and Gravity Blast is NOT the move to use with her: you should use Unknown Flare+Overrun. Unknown Flare has 30% chance to confuse the opponent, which is excellent for her, as a confused opponent wastes its turns, thus help her getting even more boosts. Not to mention that if it doesn't confuse the opponent, you still can keep wasting turns with Force Shield for free boosts. And Overrun... meh it's a 100 stab, and her using it looks quite a lot like her soku spellcard (Fantasy Nest).
My opinion: try to fight puppets that have a level equal to hers, or to netplay. You'll understand that she's far from being broken, as she will get smacked in the face more often than not. But you know, even if she gets Serious and stomp the entire opponent team, that's just how it happens most of the time with any puppet: a match is often won/lost way before the very end.