The second semifinals match of the Pokémon World Coronation Series Masters Eight Tournament is about to commence, where the winner will earn the right to face Monarch Leon in the finals. At one end of Wyndon Stadium, Goh is giving Ash and his team words of encouragement, while at the other end, Diantha is doing the same with Cynthia, believing she could be the one to end Leon's unbroken winning streak. To the surprise of the famous actress, Cynthia reveals that she intends to retire from battling once the tournament has ended.
The first Champion of Alola and the world-famous Sinnoh Champion both enter the battlefield. As per usual, Dan explains the rules: the match is a six-on-six Full Battle, with no limits to how many times each Trainer is allowed to change their Pokémon, and each of them may only use one of either Dynamax, Mega Evolution, or Z-Moves per battle. While the announcer wonders if they will use the same cards they did in the quarterfinals, the two Champions send out their first Pokémon. Ash's choice is his Dragonite, while Cynthia unexpectedly leads with the Forbidden Pokémon Spiritomb. Backstage, Diantha notes that Cynthia has instantly seized control by leading with a Pokémon that no one anticipated. As the signal to start the match is given, Ash orders a Draco Meteor as his first move, only for Dragonite to be struck back by Spiritomb's Sucker Punch. After getting back on its feet, the Dragon Pokémon completes the use of Draco Meteor, scoring a direct hit, but Spiritomb merely shrugs it off and laughs mockingly. Ash's next attack is a Dragon Claw, but Spiritomb stops Dragonite in its tracks by using Hypnosis, causing Dragonite to fall asleep. With Dragonite left vulnerable, Spiritomb proceeds to use a flurry of Dream Eaters, gradually draining away Dragonite's energy. Ash's pleas for his Pokémon to wake up prove fruitless, with the end result of Dragonite being defeated in its sleep without managing to deal any real damage to Cynthia.
While Ash recalls Dragonite and prepares to send out his next Pokémon, Cynthia abruptly recalls Spiritomb as well. Both Trainers' second Pokémon, Gengar and Roserade, enter the field simultaneously. Roserade's Bullet Seed fails to do much damage due to being not very effective, while Gengar scores a direct hit with Shadow Ball. The next exchange of moves comes in the form of a Will-O-Wisp and a Leaf Storm, with both attacks striking their mark. With Roserade now suffering from a burn, Cynthia recalls it and returns Spiritomb to the battlefield. Yet again, another exchange of attacks is made, this time between a Dazzling Gleam and a Sucker Punch. While both sides suffer super effective damage and get back up, unlike Spiritomb, Gengar ends up falling back down and fainting, increasing Cynthia's lead.
Once more, Ash recalling his fainted partner is accompanied by Cynthia withdrawing Spiritomb, this time in favor of Togekiss. Just as Cynthia predicted, Ash responds by calling forth his loyal and strongest partner, Pikachu, in the hopes of turning things around. Pikachu's series of Thunderbolts fails to make contact with the swiftly moving Flying type, who strikes back with Air Slash. When Togekiss follows up with Zen Headbutt, Ash finds Pikachu flinching and unable to prevent himself from being hit. Diantha and Leon realize that Togekiss's Ability, Serene Grace, helped to make this happen. Making yet another switch, Cynthia sends out her Gastrodon to take the type advantage over Pikachu. Aiming to take out Pikachu here and now, she orders an Earth Power. Pikachu evades the attack by jumping high into the air using the slabs of earth flung up by it, once again following Cynthia's prediction. When Pikachu starts using Iron Tail next, Cynthia has Gastrodon use Stone Edge. This time, though, things are going according to Ash's plan, as, instead of directly attacking Gastrodon, the Iron Tail slices off the tops of some of the stone pillars created by Stone Edge and sends them flying at Gastrodon. While Gastrodon manages to catch the rocks and absorb the impact, this leaves it immobilized and defenseless, allowing Pikachu to use Quick Attack to smash through the rocks and into Gastrodon, finally giving Ash a knockout of his own.
Cynthia admires Ash's skill to find an opportunity in the midst of a crisis and Pikachu's ability to exploit it as she recalls her fainted Pokémon. Spiritomb then rejoins the battle yet again; however, Ash is now ready for it and subsequently tells Pikachu to spin around while using Thunderbolt. The resulting vortex of electricity not only successfully repels Spiritomb's Hypnosis, but also strikes it at the same time. Ash identifies the strategy as Counter Shield, a tactic that he came up with while he was traveling through Sinnoh and which Cynthia recognizes from the Sinnoh League. Ash assures Cynthia that he's grown much stronger since then and has Pikachu ensnare Spiritomb in an Electroweb, successfully avoiding a Sucker Punch in the process. As Pikachu goes for a finishing Iron Tail, Cynthia orders Spiritomb to do something unspecified. Moments later, Pikachu's move connects, causing the Forbidden Pokémon to retreat into its Odd Keystone and the audience to cheer. However, as Dan inspects Spiritomb, a dark energy suddenly emerges from the keystone and envelops Pikachu, causing him to seize up. The announcer recognizes Spiritomb's last-second move as Destiny Bond, whose effect has now activated. As a result, Pikachu is instantly drained of all his remaining strength and faints alongside Spiritomb. With this double-knockout, Ash's ace has been taken out and his ability to use 10,000,000 Volt Thunderbolt has been eliminated, giving him a severe handicap as Cynthia continues to stay in control of the battle.