>>27526235By having her more shocked and disillusioned when he acts immature. By attempting to be more forward with her feelings only for Ash to remain oblivious, causing frustration. By attempting to do things with him but failing to keep up, frustrating both but leading to Ash being more understanding and Serena trying harder. Maybe Greninja's dark type is what causes Pancham to evolve, hindering his dancing ability. I'm just spitballing here, there are a thousand ways they could go about this.
>>27526530True. Most of their conflicts are resolved in an episode. Greninja's was better developed, but it was still really last minute, and nothing really alluded to a special bond prior to Olympia outright stating it at the end of XY. I also wish he showed more personality. I envisioned chuuni, acting all cool with ninja poses, then a cutemon like Eevee bats at his tongue. Maybe work that into Hawlucha teaching his whole team to pose.