Their route took them up into the mountains, on the way towards Celestic Town, both to visit the area in a more general sense and because there was a Contest hall there.

Ash had swapped out some of his Pokémon in Hearthome, bringing out Koraidon so she could meet Sandshrew, and that had led to a moment when Sandshrew had reached out to touch Koraidon's nose.

And then a moment when Koraidon had realized that an Ice-type touching your nose meant that the nose would inevitably end up quite cold.

With that sorted out, though, one fine morning found them by the side of the road as everyone worked on training.

"It seems a bit odd that we're going from place to place, and yet we're standing still," Sandshrew said. "That's strange, right?"

"It is, a bit!" Ash admitted. "But it's the way we do things… I guess it's so there's time to practice, and then time to think about what to do next. It's us trainers who do a lot of the walking from place to place, and it lets you guys rest… or, that seems to make sense, anyway?"

He shrugged, and Sandshrew nodded her understanding.

"That does seem to make sense," she agreed. "Is that something you've thought about a lot before?"

"Nope!" Ash replied. "But when I was starting out, I had two Gym Leaders with me, and I guess Brock and Misty really helped me learn some good habits. And now I'm actually thinking about them."

He shrugged, then turned his attention to today's main focus.

"Okay, Zorua, ready for this?" he asked.

Zorua nodded. "Ready," he confirmed.

There was a crash as Cynthia's Jangmo-o headbutted her Lucario, and Ash glanced over before returning his focus to Zorua – and to Swellow and Staravia.

"So what we're going to do today is about angles of attack," he said. "Swellow already knows how this works really well, Staravia, so you're going to be learning from him, okay?"

"Got it," Staravia agreed. "I don't know what angle of attack means, though, so… not that bit."

"In that case, I'll explain," Ash replied, readily enough. "So what I mean when I say angle of attack is that… if you're trying to hit a Pokémon, just hitting them often isn't enough. It depends on what's behind them, as well. Like… if you dive at a Pokémon at top speed, and they dodge out of the way, you slam into the ground. But if you fly along the ground and attack, and they dodge out of the way, you might not hit anything and if you do it's at a much less awkward angle. You can kind of… bounce off the ground."

He glanced at Koraidon. "That applies to you, as well, Koraidon, even though when you're using Collision Course you've got way more ability to just flatten what gets in your way. Because if you're in a team battle, being able to line it up to hit both of the other Pokémon at once is really good, while, uh… hitting your teammate is bad."

"Thanks, dad!" Koraidon said. "I didn't realize that before."

She sniggered. "But, yeah, it sounds obvious when you say it but that kind of thing actually does matter."

"Which is why I've asked Zorua to help," Ash explained. "Since he's a Ghost-type, a lot of attacks just pass through him, like Quick Attack and Extremespeed… which means what I'm going to ask you to do is to use those attacks on Zorua from the side, and get used to both coming around to attack and also steering properly. Got it?"

"Got it," Staravia agreed.

"Okay, Swellow, let's show how this works," Ash instructed, and the Flying-type banked around. He skimmed close to the grass, then blurred into an Extremespeed attack, and passed right through Zorua – zipping past Koraidon close enough to ruffle her feathers, but not close enough to actually hit her.

Staravia gave it a go next, and found out that it wasn't as easy as it sounded. His wingtip clipped the grass slightly, and he cartwheeled through the intangible Zorua before Koraidon reached out a paw to catch him.

"You okay?" she asked.

"Ow," Staravia replied, which wasn't technically an answer. "Okay, I need to work on this."

"And once that's worked out, I'm going to have Buneary join in," Ash warned him. "This time, what that means is Buneary's going to be trying to intercept you. When Buneary's using High Jump Kick, he has to be careful to not crash, which is the same kind of thing, but Bounce is different. So it's about judging which is the best option…"

"What do you think?" Dawn asked. "Are you getting on okay with being bigger and heavier, now?"

"Now that I've had a chance to adjust, yeah," Grotle agreed, nodding. "It means we're going to have to work on different routines, though."

Dawn got the gist. "Right, so Seed Bomb can't blast you around so much, but it can still be used to hit someone else… here's an idea to work on, actually. Throw out a Seed Bomb and then try and hit it with a Razor Leaf while it's in mid-air – aim to get the point of the explosion exactly at the same distance every time!"

"Oh, I get it," Grotle realized. "That's control, and it means I can hit a Pokémon even if they dodge a bit."

"That would be pretty neat to work with in battle," Sneasel voiced. "Though I guess in doubles matches we'd be doing things differently."

"I did actually want you to work with Chimchar," Dawn told Sneasel. "He's good with fire, but as Chimchar evolve they pick up Fighting moves, too… Riolu, you can help if you want?"

"Oh, that would be great!" Riolu said. "Though I don't actually know how you want me to help. How do you want me to help?"

"I'll explain, if you want," Sneasel suggested. "The first bit is going to be learning to move in a Fighting-type way, and you can actually help out a lot there – I know a Sneasel way of doing it, but Chimchar doesn't necessarily need that. We'd do much better if we work it out between us."

Riolu brightened. "I get it, yeah!"

He rubbed his paws together. "How does that sound, Chimchar?"

The Fire-type squared his shoulders. "I'll give it a go," he decided. "I don't know how well I'll do, right now, but I'll give it a go."

Dawn smiled. "That looks like you've got something to work with," she said. "And, Piplup… I know it's not great, but if you could practice using Bide inside your Whirlpool to bring out a spectacular finish, then you'd be a good target for Grotle too."

Piplup sighed, then twirled himself up a Whirlpool.

He didn't get much further than that, though, before a Pokémon went splash down a nearby waterfall.

"What was that?" Dawn asked, shading her eyes to look into the water. "Hold on a moment… that looks like a Shaymin! I haven't seen one of those since my trip to Hisui…"

Dawn retrieved Shaymin from the river, with Piplup's help, and by the time that was done Sneasel had gone to fetch Ash and Cynthia. The other two trainers and their Pokémon arrived, Ash ready for a rescue mission into the water that turned out to be unnecessary, and Shaymin shook herself out before sighing.

"I have had a terrible day," she said.

"Oh!" Cynthia said, suddenly very interested. "You're a Pokémon who can speak to humans? Is that telepathy, or aura, or are you simply speaking in our language because you've learned it in the normal way?"

"If it is telepathy, I'd like to learn more about how to do that," Latias admitted. "Mew can do it, but they're not great at explaining how they learned, but Shaymin isn't Psychic-type so however she learned…"

She glanced at Ash. "That makes sense, right?"

"It probably does, yeah," Ash confirmed. "You could ask Mewtwo about it, too, he's the one who taught Mew…"

"I'll have to think about what would work better," Latias agreed.

"What's a Mewtwo?" Shaymin asked.

"He's kind of private," Ash explained. "But, uh, what kind of terrible day have you had?"

"Giratina!" Shaymin said. "I fell into this weird place, and then there was Giratina right there! And I was scared and tried to run away, but the whole place was so full of corruption and poison and things like that, and Giratina was chasing me, then there was a big explosion and I fell back into – and now I'm completely lost!"

Ash, Dawn and Cynthia exchanged glances.

"Giratina was chasing you?" Ash repeated. "Why would she do that?"

"I don't now why she'd do that," Shaymin replied. "Why do you expect me to know? I've told you everything I know."

"Giratina isn't a she," Latias told Shaymin.

"What?" Shaymin asked, now very confused. "But that, weird Pokémon there just said she."

"That's because Ash is male," Latias replied. "I'm female, and so are you, so neither of us should use she for Giratina."

"You're explaining about how to talk about Giratina, right?" Dawn checked. "I know it's a bit difficult to get your head around…"

"How exactly did I end up landing next to people who know about Giratina?" Shaymin demanded.

"Would you rather you didn't?" Riolu asked, confused.

"I don't want to answer that," Shaymin muttered.

"So… I guess what I'm trying to say is, I don't really think Giratina would try to hunt you down or hurt you?" Ash said. "But – uh, I don't actually know Giratina. I just know what Dawn has said and what Dialga and Palkia have said."

"...do you have any idea how insane what you're saying sounds?" Shaymin asked. "Why would Dialga and Palkia… how did you meet them, anyway?"

"I'm their youngest brother," Ash explained.

Shaymin just kind of stared at him for a bit.

"What?" she asked. "I just… so you're a Legendary Pokémon yourself, I guess."

"Or a mythical," Cynthia contributed. "The definition of a Mythical Pokémon as opposed to a Legendary Pokémon is quite vague and I've never really got a straight answer from anyone about how they separate those categories. But by at least one list that I've seen, Shaymin would be a Mythical Pokémon. As would Darkrai, and we've met one of those as well."

She shrugged. "Unless you know any different?"

"I don't know what the difference is, no," Shaymin said. "That's… okay, go back to how you're the youngest brother of Dialga and Palkia?"

"And Giratina!" Ash said. "So, uh… my dad is the creator of the universe, and he created some Pokémon directly. Those are his kids, and then I'm his son as well but that's sort of different because my mom was involved too. I didn't actually know I was a Pokémon at first, I thought I was human until I took a magic potion."

"No, this sounds more insane now," Shaymin said. "So… okay, hold on. How does that work? If the creator of the universe created Pokémon directly…?"

"What else would you call us?" Koraidon asked, curious, then pointed at Ash. "Dad created me directly, and that was sort of by mistake, but I don't mind… and we agreed that he's my dad, and Miraidon and Mew's dad too, though both of my siblings were different. Miraidon was deliberate and Mew was a sort of computer program until Dad made them real."

"This isn't actually helping," Shaymin mumbled. "Okay. So… so… if you are Giratina's, uh, brother, but you've never met… them… then how do you know?"

"I've met him," Dawn said. "I also met someone who was working with him to mess up the world, but… there was all kinds of stuff going on that meant that both Giratina and Volo were really messed up inside. And… I helped with that, for both of them."

She smiled. "Giratina was upset that nobody really saw him properly. It was always Dialga and Palkia, but not Giratina, even though he's as important as they are."

"Then how does that relate to how, uh, he was chasing me around?" Shaymin asked.

"We don't know," Ash said. "Maybe Giratina is mad with you. But we'd want to actually ask her before we decide that."

He frowned. "And, if she is causing trouble… then, it wouldn't be the first time, either. Like how Groudon and Kyogre were causing trouble. But I don't want to make up my mind before meeting her for myself. Did she say anything? Or try to attack you?"

"I didn't notice any attacks, but I was too busy running away," Shaymin said, stubbornly. "Giratina's big and scary! Would you just stand there?"

She looked at the trainers and Pokémon.

"I'd like to meet my uncle!" Koraidon said. "But even if that wasn't who we were meeting, still yes!"

"Of course!" Riolu said.

"I've seen Ash stand there and watch while three Legendary Pokémon are about to attack him," Pikachu volunteered. "Seriously. That was back when we thought he was human, too."

"I'd be too busy wanting an interview," Cynthia admitted.

"Of course you would," her Lucario agreed.

"And a battle."

"Naturally."

"When I first saw him, I was… scared, yes," Dawn admitted. "But I knew that he was hurting, the same as Volo. I knew he was Ash's brother. So… I couldn't. Because I trusted my team to keep me safe, and because doing anything but standing there and trying to help Giratina… was wrong. Knowing what I knew then, and what I know now, I felt I had to try and help him."

"She's my sister," Ash said. "And even if she wasn't… she's a Pokémon. And yeah, sometimes Pokémon are scary, but… Giratina can't help how she looks. She just looks like that, that's how dad made her, and… that's how everyone reacts to her. So I feel like people should just give her a chance."

Shaymin looked embarrassed.

"I… uh," she began. "I was hoping you'd say something else, but… now I feel really bad, actually."

"Then…" Ash began, turning to get at his saddlebags. "How far away did you meet Giratina? I guess that must have been Giratina's world, and then you ended up out here, but… how far did you go?"

He glanced up. "Dawn, do you know much about Giratina's world?"

"Only that he has one, and that it's… different?" Dawn replied. "It's a mirror of our world, because Giratina is associated with mirrors."

"Then… well, uh," Ash said. "If the Reverse World is a reflection, then, going a mile in this world might be going a mile in her world. Or maybe not, but if it isn't then we don't really have a way to know. But if it is a reflection, then we can just go right there and meet her, right? If Shaymin didn't go far, anyway."

"You're talking like this is even possible," Shaymin said. "I… actually I was hoping to get a lift back to Gracidea, where Shaymin live. But how could you possibly go to Giratina's world just like that?"

"If I can, it would mean Unown's help," Ash replied, taking out Unown's Pokéball and sending them out. "Is that something I can do?"

"Reviewing conversation for context," Unown stated. "You wish to: open a portal to the Reverse World. Is this correct?"

"Yeah," Ash agreed. "Is that something I can do?"

"It is," Unown told him, transitioning to Alphabet Form. "Awaiting confirmation."

"Why do you even have an Unown?" Shaymin said, now completely lost. "I thought those were vaguely useless."

Latias giggled.

"It's probably for the best that Unown usually don't do anything, because they're really good at doing something if something is what they're trying to do," Pikachu said. "At least, when they work together. And especially with Ash involved."

"I just want to check, Ash," Cynthia said. "Do you think this is a good idea?"

"Yeah!" Ash said, then paused, and frowned.

"I think… yeah," he said, more soberly. "I want to meet Giratina, I want to meet all my siblings and Giratina's one of the last ones left, and – and we know she's nearby, right now. Or she was recently. And otherwise I might never get a chance."

"I think it's a good idea, dad," Koraidon volunteered.

Zorua raised his paw. "Woo."

"All right," Ash said, nodding. "Unown – open a portal to the Reverse World."

Unown pulsed gold, and so did Ash's ring. A large hole opened up in space, tilted at a forty-five degree angle to the horizontal, and Ash wobbled a bit before almost falling over.

"That was, uh," he said, bracing himself, then relaxing slightly as Koraidon loped forwards to support him. "That was more tiring than I was expecting… thanks, Unown."

A camera had appeared in Cynthia's hands, and she was already taking photos.

The Reverse World looked… alien.

And beautiful.

The ground was contorted and folded into strange shapes, where the direction of up or down seemed to be entirely unique for each part, except that if there was a flat surface you could generally treat it as a floor and be right. The area they'd arrived in had a small sphere covered with grass, through which a river flowed endlessly in a circle that both began and ended in a pond, and some way overhead was a waterfall that rushed over a cascade before dispersing into mist.

"This is fascinating," Cynthia said, looking back at the portal Ash had made, then in a direction to the south. "And… over that way there's a forested area in the real world, and it looks like there's a kind of giant tree made of smaller trees in the Reverse World. Which suggests that it's a kind of reflection, like we thought."

"Is, uh, real world the right word?" Ash asked. "Because this is a real place."

He looked around. "You know. It's like, if we said that Kanto was the real region, it would mean it was like Sinnoh wasn't."

"That is a good point," Cynthia said. "Perhaps… the planet? That direction should be straight down, into the core of our planet, but here it's just more air with odd patches of earth and stone."

Latias was looking around. "It's amazing," she said. "But it's… misty?"

"Yeah, it is," Ash agreed. "It looks like there's that weird purple mist in every direction. What is that?"

"That's actually… weird?" Shaymin said, following their gaze, then looking around everywhere. "When I was in here before, that stuff was right around me as a haze… my flowers charged up with it, and I had to use Seed Flare. Then I ended up back outside the Reverse World."

"So it's not around us now?" Ash asked. "Huh… Latias, can you check?"

"Sure!" Latias agreed, zipping off into the distance.

"If it's not around us, then… you mean there's a thick haze, more like fog?" Cynthia asked. "And it's not exactly here?"

"Yeah, it was thicker, I had way more trouble seeing a long way," Shaymin confirmed.

Latias was zooming in a circle around them, then came right back.

"It's sort of like a sphere of clear air, but we're not in the middle," she reported. "Once I was over there I could tell more easily."

Ash passed that on, and Dawn frowned.

"Then… maybe what that means is that where Shaymin used Seed Flare is the middle of the clear section," she said. "Which might mean that Giratina is nearby."

Ash belatedly remembered to get his Pokédex out, scanning Shaymin, and read off the information.

"Oh, huh, maybe you're right!" he said. "Shaymin can absorb toxins in the air… so maybe the whole Reverse World is like that right now? Why would that be?"

"Maybe you can ask?" Dawn suggested.

She walked to a kind of grassy hillock and put her hands to her mouth.

"GIRATINA!" she called. "WE'D LIKE TO TALK!"

"Why did you do that?!" Shaymin asked. "If Giratina heard that, now they'll know where we are!"

"That's why I did it!" Dawn explained, reaching for a Pokéball. "And I'm pretty sure he'll recognize Samurott, even if he doesn't recognize me!"

The Dark-and-Water-type emerged, standing where she could be seen, and several long moments later a shape came coiling through the air towards them.

Giratina was a kind of six-winged serpent, with a grey body banded in red and black and with golden spines, and six curling wings of shadow springing from their back.

They sped through the Reverse World, towards Dawn, and slowed a little as they got close.

"Who-" they began, then their gaze flicked to Ash. Their wings went slack, their coiling movement halted, and they fell suddenly upwards.

"...maybe should have eased her into that a bit?" Pikachu speculated.

Giratina would have hit something on the way up before recovering, but the Ghost-type happened to be intangible at the time and so just passed through.

Several seconds later, she swam back down through the slab of stone, and approached slowly before halting about twenty feet away.

Shaymin slowly shuffled until she was standing behind Cynthia.

"Who… are you?" Giratina asked, in a hushed voice. "One of you, I recognize… dimly… but I cannot see how you could be here. And then there is someone who might be my father, but who looks… different."

"My name's Ash," Ash introduced himself. "And… I'm your youngest brother. It's a weird story and we don't know the full details, but I was born human, and I only found out that I was a Pokémon a couple of years ago. And I didn't know that my father was Arceus until I met Rayquaza."

"How can you have been born human?" Giratina asked. "If you were created, then… why would you be human?"

"I wasn't really created, I was born," Ash emphasized. "My mom never knew that my dad was Arceus, and he left before I was born, I… guess I was sort of an accident? Or, he didn't mean for me to come about, anyway, and he made sure my mom was comfortable, and then… well, uh, part of why I'm here in Sinnoh is to try to find him. To just… get to know him? And ask about what happened? And… things like that."

He looked down. "I've met a lot of our siblings, now. Groudon, Kyogre and Rayquaza, and Dialga and Palkia, along with Mesprit and Azelf. And now you. So, uh… I hope it's good to meet you?"

Then Ash pointed at Dawn. "And, yeah, you should recognize her. She's Dawn, but you might have known her as Akari? She's the one who helped you and Volo, and stopped you from making a big mistake. There was time travel and stuff, so she knew me already when she met you, but I don't think she could say anything because otherwise it might break time or something? And Walking Wake and Iron Leaves made sure it didn't break time, but I can't really ask them the details because they haven't been created yet. So far I've created three Pokémon, all in different ways, but Koraidon's the oldest. She's your niece."

Koraidon waved.

"Hello, uncle Giratina!" she said.

Cynthia held up her hand.

"If it helps, I am one of Volo's descendants," she said.

Giratina just kept staring.

"This is a much odder day than I was expecting," they said. "You… are not father, but you are definitely an Arceus. How do you deal with finding out that there is more than one of a Pokémon species you had always thought was unique?"

"I don't know," Ash admitted. "I… I've been dealing with a lot, since I found out what I was. And, especially since I found out who I was. It's such a big thing, and it's – taken a while for me to really understand it. Properly."

He frowned. "I don't think I really do understand it. But… I guess what helped was to try and decide what actually matters? And what matters here is that – I've got a lot of power that I don't know how to use, so I have to be careful with it. And I've got family that I've never met. So I'd like to meet them, and you're family."

"I…" Giratina began, slowly. "I did not expect to ever see Akari again… and for her to have barely aged at all. And I certainly did not expect to meet a new brother, especially one with such a strange tale. But after the troubles of the last few years, I like the change."

"Trouble?" Ash repeated. "There's trouble? Can we help?"

"My world is a mirror of yours," Giratina told him. "When my world is damaged, your world responds. When something is dissonant in your world, then my world responds… and it has become tarnished, with a kind of poison spreading throughout."

"Oh, so that's why you were so interested in Shaymin?" Ash asked. "Because she actually did clear some of it?"

"You could have said!" Shaymin protested.

"I did," Giratina replied. "You didn't listen. Like nobody listens."

Her voice simmered with ancient rage for a moment, then she sighed. "No, that's… not true. Especially now."

Then something came through the portal Ash had left open, a kind of spindly ship, which got everyone's attention as it rose into the sky of the Reverse World before unfolding.

"Whoa," Riolu said, softly. "What is that?"

"It might be Team Rocket," Ash said, then shook his head. "No, it's not shaped like a Pokémon…"

AN:

Sibling counter increment!