Satoshi vs Korrina. Initially very disappointed until I analyzed certain parts, which happened once before in Sun&Moon battle I thought sucked. Was actually going to compare the quality of this episode/battle to some of the (pathetically) weaker showings of S&M, too. Anyway, I expected Satoshi to lose, especially after Gengar's somewhat poor display (it just didn't land enough hits) and teamwork—even though in the grand scheme of things it was crucial that Satoshi wins—with Dragonite left to take on two opponents. It's just, Satoshi has on one or more occasion lost to trainers he's won against before. This happened with Shigeru (like the most notorious example, beating Satoshi after he lost to him in the Johto League and then again after Satoshi won the Battle Frontier), some Gym Leader from Hoenn (Tessen I think?), I think another gym leader from some region, etc. Perhaps in some cases the loses were justified for him using inexperienced Pokemon like Torkoal, but it wasn't just with inexperienced Pokemon. So I feared it'd happened again, but it didn't.
After Gengar's defeat and it only landing a single attack as a halved-damaging one on Lucario, I figured Satoshi's Dragonite can't defeat the fairly powerful Meinshao and undeniably powerful Mega Lucario. I was wrong and part of me was shocked. But after rewatching, my perspective partially changed. Parts like Korrina instantly Mega Evolving her Lucario before engaging Dragonit—rather than the usual tradition of "battle in regular form for a bit before evolving"—the multiple powering-up Dragon Dances, and Dragonite's self-portraying toughness helped add reason & logic to how it clinched the victory. Some people always have the narrow thought process of "this pokemon has more battle experience" and "it can mega evolve", so it should definitely win and/or be stronger than one Pokemon without those things, but it's evident that Dragonite's Dragon Dance uses gave it the edge it needed to defeat Mega Lucario. It used Dragon Dance to fill the gap of power it was missing from the lack of mega evolution, even though mega evolution isn't a power-up that guarantees its user being stronger than any non-Mega Evolved Pokemon. I am very glad the writers had Satoshi won this way, because also it comes full circle with how Korrina abused Lucario's powering-up Sword Dance in its first battle with Pikachu and allowed it to defeat it because of it. Good attention to detail, and Korrina got a taste of her own medicine. Additionally, it looked like Satoshi interrupted the fully concentrated state/wave of Mega Lucario during his "Aha moment", which was incredibly genius of Satoshi (also from a continuity standpoint), so the battle and victory from Satoshi is really not as bad as people think it is. (I also think that great strategy showed that Korrina and Lucario are still immature and haven't properly mastered the Mega Lucario form. Her grandfather's likely either wouldn't have lost concentration, or it would have and gotten its concentration back.) Dragonite had the right tools for the job, between flight, powering up attacks, high durability, and more. I don't think Pikachu could have won against ML if it fought it this time.
I'm glad the narrative wasn't set up so that Korrina/Lucario won to (mostly) have a stronger or specific impact on Riolu's growth, especially since they won't be proper rivals or recurring characters. Riolu can learn and grow plenty without Lucario needing to show some superiority over its trainer Pokemon. Not exactly sure what impact her Lucario will have on Riolu, but one of the things I hope is it being the way it uses Bone Rush, uniquely from the norm (breaking it up in two pieces rather than just using the singular staff). Outside its competence at wave control, I can't imagine what else it can make its own from Lucario.
Will probably give an expanded mini "review" after the subs are out, briefly going over other parts of the episode. Looking forward to rewatching with subs!