Hmm, based on my definition of pure filler, I'd say only seven episodes after Castelia's gym battle qualify. And those would be the fishing, Litwick, Cottonee, Elgyem, Audino, Archen, and Zorua episodes. All the others either had someone catching a Pokemon, rival battles, or else someone's Pokemon learning a new move or other kinds of development. Although, the Oshawott episode could probably fit into my description of filler, too, since nothing really came of it. It wasn't like the episode where it finally mastered Aqua Jet.
Okay, so yeah, eight episodes. The two episodes set to air after the mini tournament sound pretty fillery too, though. They do both also have Meowth in the title, so who knows. One also says Scrafty, but I think it's a safe bet to assume Ash's Scraggy isn't evolving anytime soon.
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