This was a great episode with plenty of intriguing things happening one after another. First of all, another mention of the League in Ash's flashback, and it more or less confirms that Kiawe is going to participate in the League. Then Giovanni's phone call to Nanu.....yep I'm now more convinced that writers are very likely incorporating the Team Rainbow Rocket plot into the anime. Then, the mention of the lore of Ultra Necrozma along with Solgaleo and Lunala......yep no doubt Ultra Necrozma is getting to play in big role at the end of the series(and not to mention Poipole being intrigued by seeing the pic of Ultra Necrozma in the book also definitely rings a bell about what role it could possibly play in the Ultra Necrozma arc).
And last of all, the battle. Damn, Kukui was right, Ash yet isn't quite ready to challenge the Ula Ula Grand Trial yet. A really hard loss for Ash and Dusk Lycanroc; the red eyes rage thing just seemed to a plot-device to make Ash lose the battle, but I guess it's just fopr the greater good anyway, Dusk Lycanroc definitely will get some great development out of this hard loss.
Overall a great episode, plenty of things happened in it to keep the plot advancing. 9/10.