Ash and Greninja are battling a Trainer with a Scizor. After avoiding Scizor's attack with Double Team, Greninja uses Aerial Ace after the Greninja copies are mowed down by Scizor's Bullet Punch, resulting in Scizor being defeated and earning Ash the victory. Ash's opponent is impressed with Greninja's speed and power, to which Ash is thankful and bows. Ash's friends approach him as Serena comments on how she knows he will win his Gym Badge, and Ash mentions how it will be his eighth Gym Badge if he wins. At that moment, a familiar voice calls out to the group as they all turn and notice that it's Sawyer.
As Squishy relaxes in the sunlight, Ash and his friends are impressed to learn that Sawyer has managed to obtain all eight of his Kalos Gym Badges, and Ash reveals that he only has seven at the moment and that Sawyer has beaten him to it. Serena asks Sawyer about what type of Gym the Snowbelle Gym is, to which he replies that it is an Ice-type Gym. Clemont mentions how Water-type Pokémon should do well against it, which sets Ash's mind on using Greninja in the Gym battle. Serena comments on how Ash and Greninja will do well in the Gym battle due to them doing so well in the battle against Diantha, which shocks Sawyer as he learns that Ash got to battle the Champion of Kalos. Ash explains that he and Greninja merged completely, which has Sawyer think back to when the same thing happened in their battle, but Ash mentions how it was different than back then. Bonnie tells Sawyer about how Greninja had a giant Water Shuriken on its back, but he soon gets confused as to what she means when she explains further. Ash decides it would be best to just show Sawyer what they mean by offering a battle, to which Sawyer accepts and asks for a three-on-three battle like the one they had last time to see how much stronger he has gotten since then.
Outside a forest, Officer Jenny, along with some of the town's people, prepare to investigate the forest. While making their way through, Manectric hears something, which catches the attention of Officer Jenny, and one of the town's people mentions that it is the same noise they had heard earlier, leading Officer Jenny to wonder what it could be. Just then the noise stops, but suddenly, wild Pokémon jump over a bush and dart past everyone before Jenny tells everyone to run when she notices something approaching them at a rapid pace. Everyone makes it out safely, but the sound of a Skiploom is heard crying out, causing Jenny to go and rescue it. Narrowly escaping with the Pokémon, Jenny makes it away safely, as Manectric sparks electricity towards the roots, and they come to a stop. Back in the forest, Team Flare are continuing with their experiments, having improved the results. Lysandre tells Xerosic to continue with the experiments before he turns his attention to Z2, telling it that they will be using it later down the road. Squishy then attempts to contact Z2 to make sure it is safe, but to no avail. Bonnie comes out to tell Squishy that Ash and Sawyer and going to battle, but notices that it seems worried about someone. Noticing this, Bonnie begins to sing to it, which relaxes it.
Ash and Greninja put their Battle Pulse Meter's on, as Sawyer asks what they are, to which Clemont explains that they're used to monitor the emotional synchronization between Ash and Greninja, which is essential to the transformation Greninja goes through. Ash and Sawyer begin their battle as Sawyer sends out his Doublade against Ash's Noivern. Ash start the battle by having Noivern attack with Acrobatics, but Sawyer goes on the defense and has Doublade use Iron Defense to reduce the damage. As Noivern continues to attack, Clemont reveals that Sawyer's goal is to tire out Noivern by blocking its attacks. Seeing an opportunity to attack, Sawyer commands Doublade to use Slash, sending Noivern crashing to the ground, creating a dust cloud, and then Night Slash. Struggling to find Noivern in the dust cloud after missing its attack, Ash commands Noivern to use Dragon Claw followed up by Acrobatics, which knocks Doublade out, earning Ash his first win of the battle. As Sawyer returns Doublade, he is impressed by how Noivern knew Doublade's position in the dust cloud, and Ash explains that it used sound waves to locate Doublade. Upon learning this information, Sawyer makes a note of the experience. Sawyer sends out his second Pokémon, Clawitzer. Sawyer commands Clawitzer to start off by using Crabhammer, which is avoided by Noivern before it attacks Clawitzer with Boomburst. After Clawitzer takes damage, Sawyer has it use Heal Pulse to heal itself, which is noticed by Clemont as he comments on how its Ability, Mega Launcher, helped it to recover. Ash tells Noivern to use Dragon Claw, but Sawyer orders Clawitzer to use a not only super-effective Dragon Pulse, but having gained a boost in power from Mega Launcher, it deals enough damage to defeat Noivern. Ash sends Hawlucha out as his second Pokémon for the battle.
As Hawlucha dodges Dragon Pulse attacks, he delivers a High Jump Kick in return, which makes direct contact. Sawyer commands Clawitzer to use Dragon Pulse again, but Ash has Hawlucha dodge it before he commands him to go for Clawitzer's claw after realizing how powerful Mega Launcher is. As Hawlucha uses Flying Press, he swoops down to deliver the attack, but Sawyer predicted his strategy and has Clawitzer use Dragon Pulse on the ground to avoid damage. Seeing this, Ash tells Hawlucha to go higher than it and use Flying Press, but Sawyer draws him in and when Hawlucha gets close enough, he has Clawitzer use Ice Beam, dealing super-effective damage and defeating Hawlucha.
Ash is impressed by how much stronger Sawyer has gotten since last time and sends in Greninja, to which Saywer views battling Greninja as great experience and starts off by having Clawitzer use Dragon Pulse, but the attack is soon dodged. After many surprising strategies from Sawyer, Ash becomes unsure as to what to do, contemplating whether to attack or wait to see what Sawyer does and in doing so, increases his pulse. Sawyer commands Clawitzer to use Ice Beam, but Greninja blocks it by using Cut before charges through and striking Clawitzer, defeating it on the spot. Recalling Clawitzer after a hard battle, Sawyer sends out Sceptile before he begins to think about how despite earning all eight Badges, he has never won against Ash. Wanting to show Ash how strong he has become, Sawyer begins by commanding Sceptile to use Leaf Blade, but their attack is countered by Greninja's Aerial Ace. The two then release a fury of their own attacks, while continuing to block their opponent's. Sawyer has Sceptile use Bullet Seed, but their attack is countered once again, this time by Water Shuriken, causing an explosion. Going for a close-range attack, Sceptile uses Leaf Blade, only for it to be avoided by Greninja before it uses Double Team, but Sawyer has Sceptile use Leaf Blade again to lure out the real Greninja by destroying its copies. After destroying numerous copies, the real Greninja is found and narrowly avoids the Leaf Blade. With close-range attacks being Greninja's strong point, Ash puts it to use by commanding Greninja to use Cut, but Sawyer has Sceptile back away to avoid the attack, before attacking from a distance using Leaf Storm, which traps Greninja in the cyclone, shocking Ash before it falls to the ground. Serena notices how Sceptile kept its distance instead of going in close like it did previously, leading Clemont to comment on how well Sceptile is both close-range and long-distance. Ash is impressed again by how much stronger Sawyer has become in such a short time, but gets back to the battle by having Greninja use Aerial Ace. Attempting to confuse Sceptile, Greninja disappears and reappears behind Sceptile to deliver its attack, but Sceptile narrowly avoids it and slams Greninja using its tail. Ash decides to battle as one with Greninja as they prepare to merge, but the transformation fails as Clemont comments on the waves separating, leading Ash to wonder how they transformed in the first place. Noticing Ash isn't going to attack, he commands Sceptile to use Leaf Storm, trapping Greninja in the cyclone again before Sceptile uses Leaf Blade to defeat Greninja, earning Sawyer his first victory against Ash, which excites him hugely. Ash makes sure Greninja is alright before he recalls him, telling Sawyer that he has certainly become stronger since last time.
Ash hands Clemont the Battle Pulse Meter, mentioning how he wonders why he and Greninja couldn't transform, which even makes Clemont wonder, but mentions that the pulses didn't overlap once during the battle. Ash decides to drop it as overthinking it wouldn't help and sets his mind back onto reaching Snowbelle City. Sawyer asks if he can join them to Snowbelle City as he wants to watch Ash win his eighth Kalos Gym Badge, which Ash allows him to join them.
As the group continue to travel, they see Snowbelle City up ahead in the distance.