Following Ash’s victory over Marnie at the Galar region’s Wyndon Stadium, our hero’s ranking is 15th!
The next day, some fans tell Ash that Leon is also battling at Wyndon Stadium! Rushing over, he just catches the end of the bout between Leon and Flint of the Sinnoh Elite Four—ending with Leon as the winner. After the match, Leon invites Ash to do some post-battle training in the mountains!
Ash marvels at Leon’s training regimen, which is filled with playing, fun, and snacks! Now this is our hero’s kind of training, and it soon becomes obvious that the two of them are just like playful peas in a pod!
Following Ash's battle against Marnie, he and Goh have spent their night at the Wyndon Pokémon Center. When Pikachu wakes Ash up the next morning, he finds Goh's bed empty and a note left by him saying that he's waiting for him at the Motostoke Riverbank, having failed to wake Ash up before leaving. Ash starts going after his friend, but before he can even exit the Pokémon Center, he overhears two children saying that Leon is having a battle at Wyndon Stadium. Not wanting to miss Leon's match, Ash rushes to the stadium, where he finds out that Leon's opponent is none other than Flint of the Sinnoh Elite Four, whom he has met before. Ash enters the stands to witness Leon's Charizard and Flint's Infernape exchanging a few blows, until Charizard manages to defeat Infernape with a Dragon Claw, adding yet another victory to Leon's unbroken streak and causing Flint's World Coronation Series ranking to drop from 7 to 8. The two shake hands and promise to battle again someday.
After the match, Ash sees Leon at the stadium's lobby, surrounded by his fans. When Leon is about to leave, Ash rushes up to him and shows him that he's currently ranked as 15th, thanks to his victory from yesterday, putting him very close to the Master Class. Leon invites Ash to do some training with him, which Ash, while surprised that Leon wants to train right after a big battle, happily accepts.
Meanwhile, at the Motostoke Riverbank, Goh is watching Grookey play with a group of Gossifleur. When one of them jumps onto Grookey's head, he makes his choice and catches this particular Gossifleur, before letting it out to play some more. Since Ash hasn't shown up yet, Goh makes a phonecall to him and is surprised to learn that he's off to train with Leon. They agree to meet back at the Pokémon Center in three hours, but just before Goh can head out to catch more Pokémon to make up for missing a meeting with Leon, Sonia suddenly pulls up in her car, having come to survey Wild Area's Power Spots. She invites Goh to come along with her to a spot where he can catch loads of Pokémon, and while he's reluctant due to remembering her less than stellar driving skills from the time they were researching legends together, Sonia pushes him into her car anyway.
Back over with Ash and Leon, while Leon has declared that they'll be training at the sea today, his abysmal sense of direction leads them in the middle of a forest, so he says they'll train at the mountains instead. He calls out his Charizard, whom he and Ash ride through the woods and into a field full of rocks, where Leon has it break some boulders with Dragon Claw. They then climb up a waterfall before Leon suddenly recalls Charizard, letting him and Ash freefall for a moment before calling out his Dragapult to catch them. They land in the middle of a herd of Wooloo and enjoy their softness for a while before following after a group of Dreepy flying by.
As Goh and Sonia make their way towards a good catching spot, Goh is surprised to learn of Leon's horrible sense of direction from her, as it clashes with the image of him as a perfect Champion. Sonia clarifies that while Leon truly is excellent in battles, his true self is far from the charismatic facade he puts up in the public, being a big kid who can't sit still if he sees Pokémon, a description that Goh also sees fitting Ash to a T. Sonia explains that as a child, Leon didn't have a lot of friends aside from her, being too busy with helping out around the house and taking care of his little brother to play with others of his age. However, once he had met Charmander, he had started learning about Pokémon battles and became surrounded by loads of people, friends and rivals alike.
Elsewhere, Ash and Leon have settled down to eat. Leon declares that today's training has been great, clarifying that to him, battling, training, and playing are all the same thing, as they all allow him to have fun while exercising alongside Pokémon, a sentiment that Ash wholeheartedly agrees on. Their moment of peace is interrupted when a pair of Corviknight appears and starts attacking the nearby Wooloo and Dreepy. Fearing for the safety of the wild Pokémon, Leon takes to the skies with Dragapult to lure the Corviknight away while Ash climbs up the cliff they had come from. While Leon manages to get onto one of the Corviknight and calm it down by covering its eyes with his shirt for a moment, Ash reaches the top of the cliff and discovers a nest with three Rookidee in it. He notices that one of them is injured and realizes the Corviknight had started attacking other Pokémon because they were trying to protect it. When a Dreepy flies too close to the nest, the still-angry Corviknight attacks it, only to inadvertently also blow the Rookidee off the cliff as well. The injured chick is unable to fly, so Ash dives after it to save it, and is narrowly saved by Leon and the calmed Corviknight. Once Leon has tied a bandage around the injured Rookidee's wing, the two Corviknight depart with their chicks. Leon notes Ash's reckless jump to save the chick, but also admits that he would've probably done the exact same thing.
Ash asks Leon what being a Champion is like. To his surprise, Leon answers that for a long time, he was scared. Having never lost a battle, he had been afraid he had hit a limit and could not improve any further. However, that had changed during his encounter with Eternatus. Being completely overwhelmed by the Legendary Pokémon's power had not just frustrated him, but also thrilled him with the realization that there are still opponents stronger than him out there, and he can still keep improving himself by aiming towards them. This revelation makes Ash's admiration towards Leon and his desire to beat him grow even stronger, which Leon is happy to hear, urging Ash to reach him at the top. They then decide to head back, only for Leon to realize he has no idea which way his car is. Hours later, the two finally rejoin an exasperated Goh and Sonia at Wyndon.