Leon didn't sleep much since Pokémon began rampaging.

The day before, he participated in a charity event in one of the towns near the Wild Area, demonstrating Pokémon battles with his Charizard and Dragapult. Children were enthralled watching Leon's Pokémon in a mock battle. In the end, they crowded Leon, praising him and asking for his autograph. Some of them vowed to participate in the Gym Challenge when they became trainers so they might have a battle with Leon. Leon experienced this more times than he could count, yet it warmed his heart.

Then suddenly, a Centiskorch Gigantamaxed in a neighboring town. Leon left to battle it with Ash and Serena. Shortly after defeating Centiskorch, the three of them flew to battle a Dynamax Pangaroo and then to a mine where a Coalossal Gigantamaxed. They reverted the wild Pokémon back to size, but the miners rebuked Coalossal and threw rocks at it, blaming it for Gigantamaxing. Ash and Serena couldn't convince the miners to understand Coalossal wasn't to blame, but Leon admired the young couple's spirit in showing compassion for the Pokémon.

Suddenly, Chairman Rose and Oleana appeared at the site, praising the three trainers for their deeds. Leon introduced Ash and Serena to Chairman Rose, and the chairman was pleased to meet Ash, particularly after hearing Leon talk about him. When Leon asked Chairman Rose if he knew anything about the Pokémon rampaging, Rose pretended to think about it and gave a peculiar answer.

"We've been researching different possibilities, but none have quite panned out. This may simply be a present danger, or perhaps it's a test needed to jump-start Galar's future."

Leon didn't know what to make of the chairman's words. He put it in the back of his head, focusing on finding a way to prevent more Pokémon Dynamaxing and rampaging. Ash volunteered to help, then his stomach growled, and Chairman Rose offered to treat everyone to a gourmet dinner. Ash and Serena happily accepted, but Leon decided to stay and help repair the mines.

But as Leon spent the next several hours helping the miners, his mind was on the chairman's words. He then recalled Rose talking about having an energy plant below Hammerlocke Stadium and flew to Hammerlocke with his Charizard. By then, it was late at night, and the stadium was closed. He then noticed a large section of Hammerlocke's wall was gone and learned from a citizen passing by that a Dynamaxed Claydol destroyed it. Leon decided to investigate other places reported to have been attacked by rampaging Dynamax Pokémon.

Leon traveled to various places in the region, including a town in the mountains, where a woman's Pangaroo Dynamaxed and destroyed much of the town. Leon assured the woman that what happened wasn't her Pokémon's fault and helped the townspeople clear out the rest of the rubble. He then went to the port town near Spikemuth and heard of Ezria taking down a Gigantamax Lapras with her new boyfriend, Timothy. Leon was astounded that Ezria gave a man the time of day, much less was dating someone, but he mainly focused on how a trainer under the chairman's payroll happened to be at the right place at the right time.

While he was in town, however, he saw a round man and a slender woman with caramel hair sitting at an outside table of a restaurant having brunch. The man was talking about his progress in the World Coronation Series, while the woman giggled at how timid her date was speaking. Leon smiled as he watched the couple cutely interact, comforted that people were still finding happiness despite the destruction.

But as he watched the couple on their date, his mind drifted. He thought of his early days as a trainer, traveling with his childhood friend, Sonia. He smiled as he remembered Sonia teaching him about Pokémon battling with a bright smile. Looking back, he realized how much he owed Sonia for his success. Chairman Rose sponsored and mentored him since before he became Champion, but all of his skills, devotion to training his Pokémon, and learning to take something from each battle came from Sonia's teachings.

Leon's smile faded as he realized he had not seen Sonia since the day he first met Chairman Rose. He knew she quit the Gym Challenge and returned to Wedgehurst, but he didn't know what happened to her after that. He's never been able to go back to Wedgehurst or his hometown, Postwick, since Chairman Rose began sponsoring him. Leon often considered visiting Postwick to visit his family, particularly his little brother, Hop, and catch up with his childhood friend in Wedgehurst. But, no matter how hard he tried, he was always busy making appearances or facing trainers attempting to knock him off the tiles as Champion and Monarch of the World Coronation Series. Leon's collection of admirers rivaled Ezria's, yet he missed Sonia more than anything else.

Eventually, Leon left the port town and returned to Hammerlocke. It was time to find out if Chairman Rose was responsible for Pokémon Dynamaxing and rampaging. He thought of sneaking his way to the Energy Plant as Charizard flew as fast as it could, though he still didn't know what he could find in the underground facility. By the time Leon came back to Hammerlocke, it was the afternoon. Citizens were cheering at the sight of him flying above them on his Charizard. Usually, he'd give a friendly greeting, but his mind was fixated on investigating the Energy Plant. But as he got closer to the stadium, he found the entrance closed, the drawbridge lifted and Venarge and a dozen agents and League Staff members blocking the street to the stadium. He furrowed his brow as it became more apparent that Chairman Rose was up to something, and that getting into the Energy Plant would be harder than he thought.

"Charizard, land over there," Leon said, pointing at Venarge and the agents and staff guarding the entrance.

Charizard growled and swooped down, landing on the street leading to the stadium. Leon climbed off his partner just as Venarge walked over to him.

"You have no business here Leon," Venarge said authoritatively.

"I want to speak to Chairman Rose," Leon said.

"I'm afraid the chairman will not see anyone at this time," Venarge said.

"Why? What's with all of this security?" Leon asked.

"There have been reports of people attempting to destroy a major Macro Cosmos operation, and so I have been made Hammerlocke Stadium's head of security here with strict instructions not to let anyone in Hammerlocke Stadium," Venarge said.

"Head of security? Why would Chairman Rose put you of all people in a position like that?" Leon questioned.

"Obviously because I am worthy of so much responsibility," Venarge boasted. "Certainly big enough to make Ezria envious."

"Ezria. Just as I figured," Leon thought.

"And what is this major operation?" He asked.

"That's confidential information," Venarge said. "Now, get lost."

Leon frowned and stepped back over to Charizard. He rubbed his chin in thought as he scanned the building, trying to think of a way to sneak in.

"I could try flying around the stadium, but there aren't any entrances on the other side," he thought. "Maybe Raihan knows a secret way in. It's his stadium after all, and-"

"Hey, Leon!"

Leon turned his head and his eyes widened to see Ash, Serena and Pikachu flying over to him on Dragonite. They were followed by Ash's Gengar holding two men, a tan boy and a Raichu using Psychic. Leon looked at the man with the "H.A.K." shirt curiously, wondering if he had seen him before. His train of thought was interrupted when Venarge noticed Coovers and Goh with Timothy, Ash, and Serena, and his eyes widened.

"There's the enemy! Shoot them down!" He shouted.

"No, wait! Don't!" Leon shouted.

The agents turned to the trainers heading toward the stadium and immediately took out their Pokéballs. They summoned multiple Cufant, Klang, Mawile, Bronzong, Durant, Excadrill, Steelix, and Galarian Stunfisk. Before Leon knew it, the agents' Pokémon were attacking Ash, Serena, and their friends with ranged moves such as Rock Throw, Rock Blast, Fairy Wind, Flash Cannon, and Mud Shot.

"Stop! Stop attacking!" Leon yelled.

"The two men and the Raichu are fugitives threatening the chairman's operation and must be taken down!" Venarge said.

"They can't be threats! My friends are with them!" Leon shouted.

"Then they're either tricked or in league with those men secretly. Either way, they must be taken down too," the agent said.

"I won't allow that! Charizard, Flamethrower!" Leon shouted.

Immediately, Charizard unleashed a massive stream of fire, severely damaging an agent's Klang. The agents next to the one with the Klang noticed and ordered their Pokémon to attack Charizard, but Charizard unleashed another Flamethrower, driving them back. Just then, Leon heard a scream of agony and he looked up to find Gengar stuck in midair with a Bronzing using Confusion on it, leaving it open. Enemy Pokémon attacked Gengar relentlessly until the Shadow Pokémon couldn't take it anymore. Bronzing released it from its psychic control and Gengar, Timothy, Coovers, Goh, and Electchu began plummeting to the ground.

"No!" Leon shouted.

"Oh no!" Serena cried out.

"Dragonite, grab them!" Ash shouted.

Dragonite swooped down to catch their friends, but Leon knew it couldn't save all of them. He raced over to them with Charizard following him, determined to save them with his partner, but as he ran, the man in the "H.A.K." shirt took out a Pokéball and threw it toward the ground.

"Shockwave, catch us with Psychic, now!" He shouted.

The Pokeball opened, and Shockwave appeared on the ground with its eyes instantly glowing blue. It caught Timothy, Coovers, Goh, Electchu, and Gengar with Psychic just as they were a foot away from hitting the ground. Leon sighed in relief, and Dragonite landed for Ash, Serena, and Pikachu to get off and help their friends to their feet.

But just as Ash returned his unconscious Gengar into its Pokéball, the agents' Pokémon attacked again with a volley of rocks, white beams, balls of mud, and other attacks.

"Quickly, into the Pokémon Center!" Coovers shouted.

Everyone rushed to the Pokémon Center near the stadium entrance with Leon and Charizard following behind. As soon as they entered the Pokémon Center, Coovers, Ash, and Goh rushed over to the front desk. The rest took a moment to catch their breath by the entrance.

"Nurse Joy, we need you to heal our Pokémon as fast as you can!" Goh demanded.

"I'm sorry, but I'm healing other people's Pokémon. I can't heal your Pokemon right away," Nurse Joy said.

Coovers took out his badge and said, "Normally, I would respect that, madam, but I'm an officer of the International Police, and for the sake of your entire region, our Pokémon must be healed immediately."

Nurse Joy paused in befuddlement and said, "Very well. Please put your Pokéballs on this tray."

Coovers put all six of his Pokéballs on the tray while Goh and Ash gave Nurse Joy the Pokéballs for Raboot, Bunnelby, and Gengar. Coovers, Ash, and Goh turned around to rejoin the group just in time to see Leon walking over to them, his eyes on Coovers.

"If you're part of the International Police, then do you know what's going on?" He asked.

"Long story short, Chairman Rose has a dangerous Pokémon named Eternatus in an underground facility. He hopes to extract the Galar Particles from Eternatus to gain unlimited energy," Coovers said. "I was assigned to find proof, and with Timothy's help, we got a video of Ezria admitting to everything. Now Galar Particles are escaping the hanger, causing Pokémon to Dynamax and rampage."

Leon stared at Coovers with his mouth hung open for a moment and looked down in disbelief.

"So, it's true. Chairman Rose is behind this destruction," he said. "And Ezria and Venarge are a part of this too?"

"Ezria, Venarge, Oleana; basically everyone in the chairman's payroll," Timothy said, stepping in.

"This is a lot to process," Leon said.

"I couldn't believe it either," Ash said.

"The chairman was so friendly it was a shock when we found out," Serena said.

Leon stayed silent for another moment before he looked back up at Coovers.

"Do you have a plan to stop him?" He asked.

"Roughly. My superior is in Galar, but he's in Wyndon. We were hoping to storm the stadium and nab the chairman before those agents shot us down, and two of our friends are looking for two special Pokémon named Zacian and Zamazenta that might subdue Eternatus for good," Coovers said.

"That doesn't sound like a solid plan," Leon said. "How will these special Pokémon stop it?"

"Apparently, they were the Pokémon the two heroes in the legend used to stop the Darkest Day," Goh said. "These Pokémon live deep in the Slumbering Weald. We have to hope Gwen and Sonia will find them, and they will be our ace in the-"

"Sonia?!"

The lobby became silent. Leon shouted out his childhood friend's name as though Sonia participating in a dangerous mission was more horrifying than a Pokémon endangering the entire region. At that moment, Coovers remembered how Sonia acted in Circhester when Leon was brought up, and he grew concerned with how her childhood friend was suddenly afraid for her life. Whether Leon was concerned for Sonia as his friend or something more, Coovers didn't know, but he felt his hope to be with Sonia threatened.

Suddenly, the ground began to shake, and an explosion was heard outside. Timothy, Coovers, Ash, Serena, Leon, Goh, Electchu, Pikachu, Charizard, and Dragonite ran outside and saw a massive red light coming out from the roof of Hammerlocke Stadium. The light shot high into the air, creating a dark red vortex floating above the entire city, then broke into separate lights firing in all directions. The ground shook a second time, scaring the agents guarding the stadium.

"Oh no," Timothy said.

"What's wrong?" Serena asked.

"That light came from underground," Timothy said. "That can mean one of two things: either Chairman Rose's people just lost control of the Galar Particles coming from the core again..."

"Or Eternatus has escaped and is bringing back the Darkest Day," Coovers finished.

Serena's heart sank, and Ash clenched his teeth, staring at where the red light came from. Timothy, Coovers, and Electchu looked at each other in dread, feeling they might have failed their mission. Leon, however, looked at Hammerlocke Stadium with a serious look in his amber eyes. He didn't know the full extent of Eternatus' power, but it was enough to endanger his home by causing Pokémon to Dynamax and rampage. No matter the cost, Leon was determined to face the threat head-on, even if he had to do it alone. For his friends. For the helpless Pokémon forced to Dynamax. For every soul that had already gone through so much because of Chairman Rose's plan.

For Sonia.

Just then, a burst of light shot out from the stadium's tower, creating a large hole. Leon's frown deepened and it was clear Eternatus escaped from the Energy Plant. Charizard lowered its head, knowing what was on its partner's mind, and Leon climbed on its back.

"What are you doing?" Timothy asked.

"That hole can get us inside the stadium. We have to stop Eternatus before it escapes into the city," Leon said.

"Leon, wait. We can't take it down without Zacian and Zamazenta," Coovers said.

"There's no time. We can't wait any longer," Leon said. "Ash, with me."

"You got it," Ash said. "Serena, take care of Gengar."

"Ash, wait! We need to stick together!" Serena shouted.

But Ash didn't listen. He climbed on Dragonite's back with Pikachu, and they were up in the air with Leon and Charizard before Serena could say another word. As soon as they were in the air, the agents' Pokémon attacked again by Venarge's command, forcing them to dodge as they headed to the tower. Ash, Leon, Pikachu, Dragonite, and Charizard went through the hole and found themselves in the stadium's battlefield, where Eternatus was flying above the field, and there was a large hole in the ground and the roof.

"So, that's the Darkest Day," Ash said.

Leon hummed in acknowledgment.

Eternatus turned to the trainers, and it let out a low growl. The core inside its cage of appendages glowed, firing a gigantic pink and white beam with light purple sparks.

"Quick! Dodge it!" Ash shouted.

Charizard steered away, but the beam grazed Dragonite's as it moved away. With a howl, Dragonite fell headfirst toward the ground and pulled up at the last minute to safely land on its front. Ash and Pikachu climbed off it, and Ash kneeled at Dragonite's side.

"Are you okay?" He asked.

Dragonite groaned in response with its eyes closed. Ash gave it a sad smile as he took out Dragonite's Pokéball.

"Take a good rest," he said.

Dragonite was sucked into its container, and Ash put its Pokéball away just as Charizard swooped down and landed a few feet away from him and Pikachu. Leon got off Charizard and rushed over to his young friend.

"Ash, are you alright?" He asked.

"Yeah, we're okay," Ash said before looking up at Eternatus. "That's some serious power Eternatus has."

"I heartedly agree."

Ash, Leon, Pikachu, and Charizard turned their heads and saw Chairman Rose standing on the jumbotron. He looked down at them with a pleased smile and his hand in his pants pocket. Ash and Pikachu glared at the chairman while Leon looked at him in disbelief.

"It was once named the Darkest Day out of fear, but I renamed it Eternatus after its deep and abiding reverence. After all, it is a vital Pokémon that generates unlimited power," Chairman Rose said. "But little did I realize what unlimited power really meant."

Eternatus let out a roar and flew up toward the hole on the roof, but it ran into the barrier surrounding the field. The chairman's smirk grew.

"That barrier is for protecting audiences, but I didn't expect it to help me now," he said before looking down at Leon. "See, Leon, you and I have talked quite a bit about the future of Galar."

"This is no time for talking!" Leon shouted.

Chairman Rose shook his head and said, "Don't you see? This is all about the future of the Galar region."

"You are not saving Galar's future! You're risking it because of all the Galar Particles Eternatus contains!" Ash shouted.

"Pikachu!" Pikachu shouted.

Chairman Rose raised his eyebrow and said, "Let me guess; Timothy has told you the purpose of my operation?"

"He did," Ash said. "He also told Serena and me how this has to do with losing your dad in a mining accident."

Chairman Rose frowned and shook his head again.

"I'm going to need to talk to Ezria about how much she can share," he said. "Regardless, it's true. I want Eternatus' power to prevent any young boy from experiencing such a loss."

"But at the end of each beam, Pokémon Dynamax, and then they start to rampage!" Leon shouted.

"A very troubling occurrence, and for that very reason, I find very talented trainers like yourself and help you advance," the chairman said. "You, Ezria, Venarge; you are the strongest trainers in the Galar region. I discovered you and mentored you as a child. I allowed the Markenel twins to grow and show their full potential with their Pokémon teams by partaking in the Gym Challenge and World Coronation Series this year. For a time, I thought fate gave me three more talented trainers with Timothy, Ash, and Serena. And while there's been some disappointment, most of you showed your quality in facing rampaging Dynamaxed Pokémon long term."

"But that's not all you wanted us to do! You wanted us to capture Eternatus if it ever escaped!" Ash shouted.

"Right you are, Ash," Chairman Rose said. "Ezria is waiting at the top of the tower to capture Eternatus should it break through here, but now that you're here, Leon, it falls to you. You will capture the revived Eternatus, and then you will learn how to control it! Then, it will do as I command! I've prepared you for this moment, Leon. At this point, I won't take no for an answer to my request."

Leon couldn't believe what he was hearing. Chairman Rose: his mentor, his sponsor, his friend, had been building him up to be a part of something dangerous. It felt as though Sonia's teachings had been tainted. Sharing her love for Pokémon and how to have Pokémon Battles, potentially leading to her destruction before Leon could ever see her smiling face again. It made him sick to his stomach. He closed his eyes and lowered his head, taking a moment to keep himself together.

"Then, I will catch Eternatus," Leon said.

"Spoken like a true hero of Galar," Chairman Rose said with a pleased smile.

"But, I will only do it to quiet its fury," Leon continued. "There's already been great loss! I don't want to see any more tragedy!"

Chairman Rose chuckled with his mouth closed.

"How naive," he said.

Leon and Ash glared at the chairman's disregard. Then suddenly, Eternatus fired a massive beam at the ceiling. The barrier held for a moment before the beam broke through as though it was made of glass. Ash, Leon, and Chairman Rose gasped in shock as Eternatus flew through the hole in the ceiling. The Gigantic Pokémon flew to the top of the tower and began collecting Galar Particles all around it. Chairman Rose chuckled again and raised his hands in triumph.

"The full restoration of Eternatus is near!" He shouted. "And now, Leon, this is your shining moment! If you want to capture Eternatus before Ezria, you better hurry."

"Even if it generates Galar Particles, Eternatus is too dangerous!" Leon shouted. "Yes, I will catch Eternatus, then seal it away! Ash, let's go!"

"Right!" Ash said.

Chairman Rose's look of pride melted into a disapproving frown. It was one thing for trainers like Timothy, Ash, and Serena to be against his dream, but for the man he spent so much time and money on to be against him was trying his patience. Ezria and Venarge were now the only trainers he could count on to be loyal to the end, and yet their incompetence had already endangered his dream. In his eyes, he had no choice but to handle things himself. He took out a Pokéball from his pocket and pressed the button.

"One moment! I'm very disappointed in you!" He said as he threw the Pokéball into the field.

The Pokéball opened to reveal the chairman's Copperajah. Leon, Ash, and Pikachu stopped making their way to Charizard as the large, elephant-like creature let out a trumpet.

"Copperajah, use Power Whip!" Chairman Rose shouted.

"Pikachu, Use Iron Tail!" Ash shouted.

Immediately, Pikachu was up in the air with its tail glowing white while its opponent lifted its trunk to attack. Pikachu performed several flips before it thrust its tail down on Copperajah's trunk. The Pokémon wrestled with their trunk and tail until Copperajah lifted its trunk, sending Pikachu into the air. Pikachu smoothly landed on all fours, ready and eager for Ash to make another command.

"Wait, but Ash," Leon said.

"Remember, you've gotta go and catch Eternatus!" Ash shouted.

Leon opened his mouth to protest but stopped, realizing Ash was giving him the chance to go after the real threat.

"Yeah, you're right," he said. "Let's go, Charizard."

Charizard spread its wings, allowing Leon to climb on its back. As Charizard flew up to the hole on the roof, Leon heard Chairman Rose and Ash taking out Ferrothorn and Riolu, respectively. Leon put the battle below in the back of his mind, trusting Ash to handle himself against the chairman's powerful Steel type Pokémon. Charizard flew through the hole with Leon's eyes fixed on Eternatus. Leon didn't know how he would subdue a Pokémon he knew little about, but he wouldn't let that stop him from protecting everyone. As Charizard flew to the top of the tower, the image of young Sonia came into Leon's mind again, and he mentally decided he would fly to Wedgehurt to see her again as soon as she was safe.

"Avalugg, Ice Beam!"

Before Leon or Charizard could react, a white beam hit Charizard on its side. It roared in pain and crashed into the ground, sending Leon flying off its back. Leon groaned and opened his eyes to find Ezria standing on the other side of the tower. Knightblade and Doublade levitated above Ezria while Avalugg stood beside her. Ezria grinned deviously with her hands on her hips, relishing the sight of Leon and his partner lying on the ground.

"Well, well, well, what do we have here?" she asked.