XY128

A Riveting Rivalry! (Japanese: ライバル決戦！サトシゲッコウガVSメガジュカイン！！ Decisive Rival Battle! VS Mega !!) is the 128th episode of the, and the 927th episode of the Pokémon anime. It first aired in Japan on July 28, 2016 and in the United States on October 15, 2016.

Blurb
 It’s Ash’s Pikachu versus Sawyer’s Aegislash in the semifinals of the Kalos League! Sawyer presents a strategic challenge when Aegislash leaves the battlefield covered with fallen trees, but Ash and Pikachu figure out how to use that to their advantage, and Aegislash is defeated.

Then, something unusual happens: a double draw, as Ash’s Noivern and Sawyer’s Salamence knock each other out, and then it happens again with Ash’s Goodra and Sawyer’s Slurpuff! Sawyer’s Sceptile defeats Pikachu—and finally, Ash-Greninja and Mega Sceptile face off in an amazing battle of rivals. The battle is fast and fierce…until Ash-Greninja emerges victorious, and Ash moves on to face Alain in the finals!

Plot
The between  and Sawyer continues as Sawyer's  stands before  after it has cut down all the trees and cleared the battlefield with, limiting Pikachu's options for evading attacks. Ash wonders what Sawyer could be planning by cutting the trees down, while in the stands ponder the same question. Back on the battlefield, Sawyer praises Aegislash and Ash informs Pikachu that they need to be careful while battling Aegislash. Professor Sycamore is interested by Sawyer's battling technique, while Diantha wonders what he could be planning for Pikachu during the battle, commenting on how Sawyer has analyzed the battle so far. Alain watches the battle between the two from the stands.

Ash makes his next command, ordering Pikachu to use, but Sawyer quickly has Aegislash use to protect itself from the attack. Pikachu's Iron Tail connects with the King's Shield, causing Pikachu's stat to harshly drop as a result, which reminds Ash that attacking Aegislash will be difficult. Clemont and Tierno note how King's Shield needs to be dealt with properly and not handled carelessly. Seeing an opportunity to attack, Sawyer commands Aegislash to use, which Pikachu successfully dodges, only to be struck when he gets too close, slamming into the ground after the hit. Tierno wonders if Sawyer's plan is to limit Pikachu's speed, with the scattered logs forming unstable footing for Pikachu, whereas Aegislash is floating in the air, giving it the advantage. Sawyer continues to have Aegislash use Sacred Sword, which Pikachu is able to avoid several times until he backs himself into a corner and is hit. Ash attempts to use instead, but that is soon blocked by King's Shield once again. During Aegislash's change to its, Ash notices how it joins with its shield. He tells Pikachu that he has a risky idea, but he trusts Pikachu to be able to handle it. Sawyer quickly notices the change in Ash's expression, one he has seen numerous times. As Sawyer tells Aegislash not to let its guard down, Ash commands Pikachu to use Iron Tail, which he slams into the ground, forcing the logs all around into the air. Sawyer responds confidently by having Aegislash use, but as Ash orders Pikachu to use the logs to close in, Aegislash is unable to land a hit as Pikachu darts between the midair logs. Aegislash dices up all the logs around it but still misses Pikachu. When Pikachu finally appears to be closing for an attack, Sawyer commands Aegislash to use King's Shield. Setting his plan into action, Ash orders Pikachu to throw one of the logs, which wedges into Aegislash's shield where it would normally join to complete its King's Shield. Already in the middle of its move, Aegislash becomes stuck when it attempts to form King's Shield, and Ash orders Pikachu to use Thunderbolt, which connects and knocks Aegislash out.

With Sawyer's remaining Pokémon brought down to three, the battlefield is changed. While the field is being changed, Sawyer and Ash talk about how the latter was able to win the battle against Aegislash, and Sawyer notices that Ash has complete trust in his Pokémon and that's what makes them strong. The new battlefield is brought up and is revealed to be a desert field, and Ash and Sawyer send out their Pokémon for the next battle, and, as Serena scans the latter with her Pokédex. The battle begins with Ash commanding, which is dodged by Salamence numerous times before finally connecting. Noivern then uses but Sawyer has Salamence use  to counter. As the two attacks collide and Noivern recoils, Ash checks on Noivern to make sure he's alright. In the meantime, Sawyer commands Salamence to use. Noivern nimbly dodges each fireball flung its way, but after dodging the last, Salamence suddenly pops up in front of Noivern and uses to send him flying. Clemont theorizes that Salamence deliberately used Incinerate to guide Noivern's movements. After checking that Noivern is alright, Ash has him dodge Salamence's resumed Incinerate attacks. As Salamence winds up for another fireball, Ash has him use Boomburst to intercept it. The attacks collide and create a smoke cloud, which Ash uses to his advantage by commanding Noivern to use. Remembering that Noivern can see even in the smoke, Sawyer has Salamence use, narrowly blocking Noivern's oncoming attack. Ash and Sawyer command their Pokémon to use Dragon Rush and Acrobatics, and the two collide powerfully. After this collision, both Pokémon go down, resulting in a draw. Both Ash and Sawyer return their defeated Pokémon to their Poké Balls. Sawyer immediately sends out his fifth Pokémon,, and Ash sends out his in response. Despite having the type advantage, Sawyer appears concerned now that he is up against the only of Ash's Pokémon that he has never battled before. But he pulls himself together and commands Slurpuff to do his best.

Sawyer starts off the battle by having Slurpuff use, which Goodra intercepts with an. Slurpuff immediately uses, which is super effective on Goodra, but Goodra appears to shrug it off. Sawyer then orders as a follow up, but Ash has Goodra use. Anticipating the upcoming attack, Sawyer has Slurpuff use to raise his  before Ash orders Goodra to fire off Bide, and the attack appears to have minimal effect. Surprised, Ash orders Goodra to use Ice Beam, but Slurpuff intercepts it with Flamethrower, resulting in a large cloud of steam. Taking advantage of the cloud, Sawyer commands Slurpuff to use Fairy Wind, which catches Goodra off guard and sends it flying back. Sawyer proclaims that Slurpuff's sense of smell helped him locate Goodra through the steam, which Ash notes is just like what he did with Noivern. Slurpuff uses Flamethrower again and Ash commands Bide, and Sawyer hopes to hold the Flamethrower and push through Goodra's Bide to knock it out. After a prolonged battle of wills, however, Slurpuff's Flamethrower finally ends in a large burst. To his and Sawyer's surprise, Goodra emerges shaky but standing. As Ash orders Goodra to unleash Bide, Sawyer orders Fairy Wind, and as the attacks collide, a large cloud of dust engulfs the battlefield. When the dust clears, both Pokémon are revealed to have fainted, resulting in another draw.

Recalling their Pokémon, Sawyer then sends out his sixth and final Pokémon,. In the stands, Ash's friends worry about his prospects against Sceptile. Ash sends Pikachu in once again and immediately opens the battle with. In response, Sawyer has Sceptile use to keep him at a distance. The Leaf Storm lifts Pikachu into the air, and Ash commands him to use Thunderbolt which reaches Sceptile through the Leaf Storm and cuts it off. Pikachu then attacks from the air with Iron Tail, but Sceptile intercepts it with and manages to throw Pikachu back. Sawyer immediately orders Sceptile to use Frenzy Plant, which Pikachu tries to dodge, but it quickly surrounds him and lifts him into the air before arcing down to slam him into the ground, knocking him out.

With Ash down to his final Pokémon, he sends out to face Sceptile. Ash opens with, but Sceptile cuts through them with. Greninja then uses to approach, but Sceptile attacks with Frenzy Plant to weed out the copies. When only the real Greninja is left, Sawyer commands Sceptile to attack with Leaf Blade, but Greninja blocks Sceptile's strikes with its own. As Sceptile and Greninja square off again, both Sawyer and Ash take a breath to contemplate the events that have led them to this battle. Sawyer remembers how he started off awed by Ash and could only chase his shadow, but now he hopes that by defeating Ash, he'll be able to reach greater heights. Ash, meanwhile, silently apologizes to Sawyer for becoming scared and panicking when he felt Sawyer had surpassed him; but after that, he was able to find himself again, and he promises to show Sawyer what he and his Pokémon can really do.

Withdrawing from his contemplation, Ash yells to Greninja to go full power, and they synchronize themselves to transform into Ash-Greninja. Responding in kind, Sawyer takes up his Key Stone and Mega Evolves Sceptile. Picking up their battle once more, Sceptile uses Frenzy Plant which Greninja leaps to dodge; the vines immediately reach to pluck Greninja from the air, but Greninja uses Cut to slice through it and land safely. Ash commands Greninja to throw a Water Shuriken, which Sceptile cuts through with Dragon Claw, but Greninja is already closing the distance and uses to land a couple of super effective blows. As Sceptile reels, Sawyer orders a Leaf Storm which connects with Greninja and knocks it back. As Greninja lands, the two close again in a clash of blades, pitting Leaf Blade against Cut. With neither able to gain an advantage, they separate again and Sceptile launches a Leaf Storm that knocks Greninja into the air again. As Greninja falls, Sawyer orders Sceptile to press the attack with Frenzy Plant, but Greninja manages to orient itself and land securely atop the vines, racing along them and using Cut to slice its way out of pressure. However, the vines manage to keep Greninja from advancing on Sceptile. Ash's friends in the stands worry, while Professor Sycamore marvels at the Ash-Greninja transformation. Finally, Greninja jumps into the air, avoiding most of the vines, and uses Double Team. Ash warns Sawyer that he's giving him everything he and Greninja have, and as Greninja uses Water Shuriken, it grows to a massive size. Sawyer frantically orders Sceptile to counter with Leaf Storm, and the two attacks collide into a massive cloud of dust. As the dust clears, Sceptile is revealed unconscious on the ground, as Greninja lands beside Ash, victorious.

With Ash as the winner of the second semi-finals battle, he advances to the finals. His friends cheer and congratulate him from the crowd. Exhausted from the battle, Ash-Greninja reverts back to its normal form, while Ash, equally exhausted, congratulates it. are impressed by Ash's battle and speculate that he might actually win the League this time. From their seats, Professor Sycamore applauds the excellent battle, while Diantha looks forward to both contestants' futures and hopes there will be many more Trainers like them. Meanwhile, Alain smiles and turns to leave the stadium from where he watched the battle. Back in the middle of the battlefield, Sawyer meets Ash and reaffirms his admiration of Ash. Ash responds that they had a good battle and he was excited throughout. The two of them agree to battle again one day when they have both trained harder, had many more battles, and become much stronger. The two shake hands after their well-fought battle.

Major events

 * Sawyer's is revealed to have evolved into.
 * The Full Battle between and Sawyer ends in Ash's victory, advancing him to the finals to face Alain.

Humans

 * Jessie
 * James
 * Professor Sycamore
 * Alain
 * Sawyer
 * Malva
 * Diantha
 * Announcer
 * Referee
 * Sawyer
 * Malva
 * Diantha
 * Announcer
 * Referee
 * Announcer
 * Referee

Pokémon
Who's That Pokémon?: (US and international) Pokémon Quiz: Mega (Japan)
 * (Ash-Greninja)
 * (Sawyer's)
 * (Sawyer's)
 * (Sawyer's)
 * (Sawyer's)
 * (Sawyer's)
 * (Sawyer's)
 * (Sawyer's)
 * (Sawyer's)
 * (Sawyer's)
 * (Sawyer's)

Trivia

 * Poké TV: "Pokemon Unbelievable" focusing on some of 's, 's, and 's Pokémon, along with Sawyer's Mega.
 * Serena,, Clemont's Chespin, and Mairin narrate the preview for the next episode.
 * This episode marks the first time Ash has ever gotten into the finals of a Pokémon League Conference.
 * is used as an insert song during Ash's battle against Sawyer, when Mega Sceptile and are battling each other.
 * This episode marks the first time is knocked out during a battle since its capture.
 * This is the first time that the ' Who's That Pokémon? segment features a Pokémon that has already been featured. In this case, was featured in The Clumsy Crier Quiets the Chaos!.

Errors

 * After makes contact with 's, the animation of Pikachu's  dropping moved up instead of down, making it appear that the stat was being raised instead of dropping.
 * When Sawyer calls for Aegislash to continue using, Aegislash was shown being in instead of Blade Forme before attacking.
 * When Salamence's Dragon Rush and Noivern's Acrobatics collide at the end of their battle and create a smoke cloud, Pikachu is missing the brown patch on his tail.
 * When Goodra is using for the second time, its red glow is not visible.
 * After Greninja uses Double Team, the inside of one of the Greninja doubles' ear is cream instead of blue.
 * When Ash commands Greninja to use to counter Sceptile's, the scoreboard displays Ash's  and Sawyer's  as the two who are currently battling. Due to this, the scoreboard displays Pikachu as being still able to battle despite being knocked out previously, and Ash's Goodra and Greninja aren't on the scoreboard, despite having been used and defeated, and currently in battle, respectively.
 * Additionally, Sawyer's and  are absent from the scoreboard, too.
 * When Greninja uses Cut, it is missing the star shape on its leg.
 * When Ash commands Ash-Greninja to use Cut on Mega Sceptile's Frenzy Plant after dodging it, there is a tree in the background, despite them being on a desert battle field at that point of the battle.
 * When Mega Sceptile uses on Ash-Greninja, Greninja's giant shuriken is colored dark blue like the stars on its legs instead of light blue for a few frames as it falls.
 * Before Ash has Greninja use Cut against Mega Sceptile's Frenzy Plant, Ash's Pikachu is shown standing next to Ash, but is also shown on the right-hand side where Ash placed him after being defeated previously.
 * When Ash is declared the winner of the battle, on the scoreboard, Talonflame and Slaking's silhouettes are different from before.

Dub edits

 * An instrumental version of Stand Tall is used as background music.

In other languages
Eine fesselnde Rivalität! EP931 XY128 XY127 XY編第128話 精灵宝可梦 XY 第127集