"So, who do I battle first?" Ash asked. "Is there an order you normally do battles in, or do you take turns?"

"That… actually depends on you," Shauntal said, after a moment. "In Unova we believe in the right of a trainer to challenge the Elite Four in any order they want."

"That's a very specific right," N observed. "I'm not saying that's wrong… in fact, if anything it's sort of refreshing. It's just a bit odd that it's a right, instead of a policy."

Alder held up a hand, and put the other over his heart. "I am not good at paperwork," he confessed.

"Huh," Ash frowned. "So… does that mean that Virgil and I could battle you at the same time, in different arenas?"

"You could," Shauntal agreed. "Were it not for the fact that the Cameron-Virgil final battle demolished our spare arena."

"Seems reasonable," Pikachu nodded.

"Actually, what about if you pick?" Ash suggested. "You haven't had an official in a while, right? I can send you out first and you can tag out when you want."

"I like the sound of that," Pikachu agreed. "Hmm… let's say Caitlin. She's the Psychic type trainer, right?"

Caitlin nodded, and Ash gave a thumbs-up. "Great! I'll just make sure everyone who wants to spectate is here, now the stands are clear, and we can get started!"

"I wonder if this is the largest collection of Legendary Pokémon in one place in history," Suicune mused, looking around the section of the stands they'd taken over.

"That's an interesting question," Articuno agreed. "I think it depends what you mean by history."

"What I mean by history?" Suicune repeated. "It seems fairly simple, right?"

"Yeah, but that's what can bugger up what you're doing if you don't pay careful attention," Articuno told her. "It seems simple enough, then you realize you forgot to keep your assumptions straight and everyone's talking at cross-purposes."

She waved a wing in an expansive sort of way. "So, is history what's already happened, or is it everything including stuff that hasn't happened yet?"

Suicune blinked a few times. "That's either extremely deep, or you've had too much to drink."

"Could be both," Articuno replied. "Could be both."

She took off, floating upside down into the air, then dropped back down again when one of the Exeggcute coughed at her. "Sorry. Anyway, so, Psychic type trainer against Pikachu… anyone know what Pikachu's been working on?"

"I do," Sandile said. "But it'd ruin the dramatic tension if I told you now."

"Whatever," Articuno shrugged. "We'll find out in a moment anyway, here we go."

"Good morning, and may our battle be what on earth are you holding?" Caitlin's Gothitelle said, in what began as a benediction but turned more into a question.

"Oh, this?" Pikachu replied, holding it up. "It's a Thunderstone that I fitted a handle to."

"Are you planning on evolving in the middle of the battle?" Gothitelle asked. "That… well, I will be honest, it's a strategy where I can see some merit, but it leaves me asking why you wouldn't do it already."

"All right, begin or something," Alder called.

"Electro Ball!" Ash said, and Pikachu opened with a fastball-special of electricity which whipped out towards his opponent at blistering speed. Gothitelle reacted just as fast, first hitting it with a Thunderbolt and then using Psychic to push it to one side even as she stepped to the other.

"Calm Mind!" Caitlin instructed. "Build up some strength and then use Shadow Ball!"

Pikachu jumped into the air, forming a Surf-board under his paws, and electrified it with his cheeks before pushing it away from himself and towards Gothitelle. The Psychic-type had to interrupt her meditation to bat it away, and a moment later found a high-speed Thunderstone heading directly towards her as Pikachu used Fling.

It hit Gothitelle with a whang, staggering her slightly, but she shook her head to recover before firing a psychic attack towards Pikachu.

"Left!" Ash called. "Now right! Up – and Fly! Now back down again!"

Pikachu blurred from one place to the next, little swirls of electricity accompanying each jump or dodge as he used electrostatics to assist his movements, and Caitlin leaned forwards a little.

Then she gasped.

"Gothitelle, look out behind!"

Gothitelle looked towards Caitlin at first, then whirled to see where Caitlin was actually talking about, and the Thunderstone hit her in the shoulder with a shower of sparks.

Pikachu caught it by the handle, whirled around once and threw it again, and this time it hit a psychic shield Gothitelle had thrown up and went right through. Sparks went everywhere and it was slowed down significantly, but it didn't stop, and Gothitelle ducked only for the Thunderstone to whizz around in a tight circle and start hitting her about the head.

"What is even happening?" she asked.

"It's that Pikachu, he's controlling it with electricity!" Caitlin warned. "Nasty Plot – full power and warp the world!"

Gothitelle's power built up rapidly, and a long moment later the whole arena seemed to dissolve and be replaced by a kind of medieval castle. Gothitelle had vanished, and the Thunderstone hovered in mid-air as Pikachu wondered where to send it.

"Whoa!" Ash gasped. "Is this Wonder Room?"

"This is the Battle Castle. It's a manifestation of Gothitelle's ability to warp space, time and reality," Caitlin replied, as Pikachu called his Thunderstone back to him.

"Huh, we met one of those once," Ash frowned, thinking, then brightened. "Pikachu, speed up the Thunderstone to full speed and charge it up!"

"On it," Pikachu said, letting go of the handle again, and the Thunderstone began to whine as it orbited him faster and faster. Electric arcs fizzed around it as Pikachu increased the energy it stored as well, and after several seconds Ash pointed.

"Now, bounce it all over the place! Gothitelle's got to be somewhere in here!"

"Hmpf," Aten grumbled, as Pikachu's Thunderstone ricocheted around the Battle Castle distortion – creating visible ripples every time it bounced off something and every time it sent out a thick bolt of lightning to strike part of the scenery. "This isn't what I'd do to make a proper royal illusion."

"A royal illusion?" Zorua repeated. "Oh, you mean pretending to be a Calyrex!"

"Not at all," Aten replied. "At some point I am going to turn into a Zoroark, and I will be able to turn the whole battlefield into a proper royal fortress for myself."

He sniffed. "I am burdened with glorious purpose. This Gothitelle is just a faker."

"A what?" Shaymintwo demanded, looking up from his pizza.

At about that point, Pikachu located Gothitelle.

Gothitelle did not appreciate this.

"Well, that's annoying," Pikachu said, inspecting his Thunderstone. "The handle fell off."

He picked it up. "Oh well, it's not like I need to avoid touching it, anyway."

"I don't think I've ever seen a Pikachu do that," Caitlin confessed. "Still, he'll have more trouble with Metagross!"

She sent out the big Steel-type as she spoke, and Pikachu inspected them.

"Meteor Mash," Caitlin added, and Metagross punched down at Pikachu. He fired his Thunderstone up with a surge of electricity, blocking the direct punch and hitting Metagross with a powerful Electric attack just in and of itself, but Metagross kept pushing and not more than a second later the fist-leg pressed down onto Pikachu himself – where the murine Pokémon managed to hold Metagross' foot off the ground, through a combination of his own strength and the Thunderstone's pressure.

"I guess she's right!" Ash said. "You'll need a bit more strength for this one! Bulk Up!"

Pikachu began to glow red, and he shifted his weight slightly before pulling back a paw and using Sky Uppercut. It wasn't enough to knock the Steel-type out of the arena, not nearly, but it did spin them around as they lost contact with the ground and that caused the pressure on Pikachu to let up.

"Now, charge them up with electricity!" Ash said. "Knock Metagross off the ground and keep them charged! And use the Thunderstone trick on them!"

"Is that even possible?" Caitlin said. "Metagross, earth yourself!"

Pikachu resummoned a Surf-board, darting from one Metagross leg to the next, and began Sky Uppercutting the Steel-type to stop them from getting a foot-hold on the ground. At the same time he charged Metagross up, his Thunderstone bouncing between him and Metagross to make sure his opponent couldn't properly set up a shield, then decided that was enough and set his Thunderstone to orbit Metagross instead.

With a whannng, Metagross went flying into the air and out of the arena.

"Oh, this should be interesting," Grimsley said, pointing. "She's bringing out Musharna… remember that one?"

"How could I forget?" Marshal replied. "It's a Pokémon that can manifest halfway-real copies of things from nightmares. After the first time Caitlin battled me, Musharna just kept bringing up the previous times that Caitlin beat my Pokémon."

Grimsley sniggered. "Yeah, that's… hm."

His grin turned into a frown. "Shouldn't something be happening by now?"

"You and your trainer are very well centred," Musharna half-complimented half-complained under her breath, Dream Mist swirling around her. "It's actually quite inconvenient… hmm… ah, this should do."

An enormous, shadowy shape appeared from the mist, and snarled.

"Oh, Giratina, right?" Pikachu said.

"Yeah, I think that is Giratina!" Ash agreed, waving. "Hi! Or are you a different Giratina!"

"Well, obviously I'm not actually real," the shadowy mist Giratina replied, shrugging in a serpentine motion. "I'm a manifestation of your deepest subconscious fears about the situation, as expressed in nightmare."

"Why are you telling them that?" Musharna asked. "You're not supposed to tell them that!"

"What?" Ash replied. "That's a manifestation of Giratina, and Giratina looks scary, sure, but he's really helpful! He helped me get back to the rest of the summer camp without being rained on, once, he's really sweet when you get to know him. He's actually over there in the audience watching!"

"How am I supposed to work under these conditions?" Musharna sighed, turning to her trainer.

"No, father," Raikou said.

Ho-Oh furled his wings, then looked down at the Electric-type. "Isn't this your sister's job?"

"She's sitting over there," Raikou replied. "We can delegate."

"Hmm," Ash frowned, thinking. "Wait, I know! Pikachu, Double Team, and throw your Thunderstones!"

"Thunderstones? Plural?" Musharna asked, as Pikachu blurred into dozens of overlapping images. Then he began making throwing motions, and a dozen doubled Thunderstones flew towards her.

Much to her shock, all of them hit her.

"Did… did your Pikachu just become a Buddha or something?" Caitlin asked. "Or Arceus? I know Arceus is supposed to have a thousand arms, but I've never understood – how are those Thunderstones connecting?"

"I got to thinking!" Ash replied, as Musharna did her best to shield herself from the hail of projectiles and Pikachu floated into the air on his Surf board for a better angle. "See, Pikachu knows Double Team, and normally that's just about making illusions that aren't there, not like Zorua illusions which are there, and normally it's really limited because it's just an image of you unless you're also an expert for other reasons like Lokoko or Zacian are."

He ticked off on his fingers. "But the whole point of what Musharna does is to make sort of partly-real partly-not-real illusions that become sort of real inside the Dream Mist. That's what the Dream Mist does, at least, that's what I get from what the Giratina memeplex said-"

"Okay, okay, hold on!" Caitlin said, waving her hands. "One, how do you even know the word memeplex? I don't know what that word means, and I'm a Psychic type expert."

"Mew talks shop sometimes," Ash answered. "Actually, a lot of Legendaries do, and I sometimes help my Cresselia in understanding her powers and dreaming often involves memetic archetypes because they're at the same time simpler and bigger – they're sort of like the platonic ideal of ideas – and a memeplex is everything that is built around an archetype. But anyway the whole point of Musharna's style is to manifest memeplexes contributed by her opponent into something that's real enough to use in a battle, which is why the Dream Mist is involved, and it's pretty obvious that while most Pokémon couldn't use it without understanding the idea they're trying to make work a lot of Pokémon have an instinctive understanding of themselves. So Pikachu's making lots of Double Teams and using them to throw things at Musharna because he understands how to throw things."

Caitlin blinked several times.

"I would quite like to stop having this battle now please!" Musharna asked.

"Actually, hold on a minute," Ash requested, getting out his mirror. "Hey, pseudo-Giratina, can you use this to go into the Reverse World? I kind of want to see what happens."

Giratina looked down.

"Well, this is interesting," he said.

"I know," the other, much smaller, Giratina agreed. "It turns out that, firstly, when I'm only about ten percent real then that translates directly to linear scale when I get reified, and, secondly, that being in the Reverse World when the Dream Mist goes away means that – well, I'm not in the dream any more, because it's not there. But I'm still around, because I wasn't in the dream when it ended. So…"

Giratiny shrugged.

"And being Shiny?"

"Honestly, your guess is better than mine," the miniature Renegade Pokémon admitted. "I've only been around for a few minutes, I was basically a chat-bot until the dream ended, and I didn't know I was shiny for most of that time…"

Caitlin looked at the Pokéballs she had left, then made her decision.

"Sigilyph!" she called, sending the Psychic-type out. "Gravity and Ancient Power to make a shield!"

Pikachu used Thunderbolt, but Sigilyph deflected the attack away with a burst of psychic energy. Red-glowing rocks rose out of the ground at about the same time, and within a few seconds there was both an inner shield of rocks around Sigilyph and an outer whirling layer that began flying at Pikachu.

"Iron Tail!" Ash called. "And use your Thunderstone to smash the stones away – give me a moment to think!"

There was a whack as the first rock got hacked down by Pikachu's Iron Tail attack, then he blew another into gravel with a Thunderbolt and pinged his Thunderstone off two more.

"Suggestions welcome!" Pikachu called.

"I know, I know," Ash replied. "Uh… yeah, let's try this! Electroweb on one of the rocks!"

Pikachu used Electroweb, snagging a rock, and the strands of electricity twanged taut enough to tug him into the air. He let go after a moment, and Caitlin raised her voice. "Smack Down!"

Sigilyph imbued one of the rocks with a Smack Down, and Pikachu shot an Electroweb at a second one of the Ancient Power rocks. He missed, though, and when the Smack Down hit he was slammed into the ground with a wham.

"Ow," he said, before flipping himself upright and throwing his Thunderstone on a curving path to annoy Sigilyph. "That hurt."

"Pikachu, upside down and Sky Uppercut the ground!" Ash decided.

"Invert gravity and Smack Down!" Caitlin retorted.

Pikachu was already rising after punching the ground with a whack, and rose faster as Sigilyph inverted gravity around him. The Smack Down rock came in next, and Pikachu knocked himself aside with his returning Thunderstone to avoid being knocked out of the arena entirely.

"Now, Electroweb again!" Ash said, then winced as Pikachu missed for a second time. "Wait – Electroweb your Thunderstone!"

Realizing what Ash was getting at, Pikachu brought his Thunderstone right up close before tethering himself to it. Then he pulled himself through the air, ducking underneath one rock and avoiding another.

"Sky Uppercut the rocks around Sigilyph!" Ash said.

"Sigilyph, look out!" Caitlin called.

"So… if I'm following this," Shauntal began, slowly. "Pikachu avoided being knocked down into the air and then knocked rocks surrounding Sigilyph so they went upwards, but that actually knocked them towards Sigilyph because of the gravity effect Sigilyph was using to push Pikachu away?"

Alder looked blank. "Why do you think I'd know?"

Shauntal shook her head. "You have no intellectual curiosity about how these things are done."

"Reuniculus," Caitlin said, sending out her next Pokemon. "Enough with anything even resembling subtlety. Hyper Beam!"

Quick as a flash, Pikachu whipped his Thunderstone around and used it to block the attack. The initial energy surge blasted it away, but that gave Pikachu enough time to dodge and use Agility, and he sped around half the arena as his Thunderstone bounced around.

Each bounce sped it up, and it came back to Pikachu in time to block the last part of Reuniculus' Hyper Beam, then he flung it up at his opponent and she raised a Reflect shield to fend it off. That was enough to stop the Thunderstone, which bounced with a sound like a thunderclap, but Pikachu just shrugged and fired a Thunder attack at Reuniculus as well.

"Fly up!" Ash called. "Mix the attacks so Reuniculus can't shield properly!"

"Can't you just be content with being a ridiculous electrokinetic?" Reuniculus demanded, gathering psychic energy in her hands before sending it surging out at Pikachu.

"My trainer uses a junior creator deity to check if the shops are open!" Pikachu replied, hiding behind his Thunderstone for a moment before flinging it back at Reuniculus with an Electroball following it. "Excuse me for staying ambitious!"

"Well, five Pokémon down and one to go," Zacian said. "I wonder what comes next."

"Hmm," Snorlax hummed, clearly deep in thought. "I think… a Psychic type."

"Did you come up with that yourself?" Zacian asked, sounding amused.

"Mostly," Snorlax yawned. "Oh, look, it's a Gallade."

"Ah!" Zacian straightened. "This should be interesting! I wonder how this Gallade will combine teleportation with measure… and if they'll combine it with measure, come to think of it. Keldeo doesn't."

"Gallade… you know what to do," Caitlin summarized.

Gallade nodded, saluting with a Psycho Cut blade, then darted forwards and swiped at Pikachu.

The Electric-type brought his Thunderstone up to block, flicking it back and forth to absorb three successive attacks, then Gallade used his own psychic powers to forcibly yank at the Thunderstone and pull it away from Pikachu. That wasn't enough for him to overwhelm Pikachu's electromagnetic control of it, but it did create enough of a gap that Gallade was able to hit Pikachu directly and knock him halfway across the arena.

"Pikachu, are you okay?" Ash asked, once his starter had slowed to a halt.

"Yeah, I think so," Pikachu replied. "Phew…"

"I think it's time for that last trick!" Ash said. "Charge up! Thunder Armour!"

Pikachu's cheeks sparked, and electricity flowed over his body from ears to toes. It formed a complete, sparking layer over every single part of his fur, and after a nod from Ash Pikachu darted forwards again.

Gallade teleported in, already swinging his Psycho Cut blade, and Pikachu held out a palm which fizzed and cracked with lightning. Some of the Thunder Armour spiked out, then imploded, and a burst of electrical repulsion knocked Gallade staggering backwards before he could complete his attack.

Then the Thunderstone hit Gallade on the side of the head.

Shaking it off, Gallade teleported back to get his bearings, then teleported in again. This time his attack was faster and connected, but there was a spray of sparks and it was violently repulsed all over again from Pikachu's fur – and Pikachu used both forepaws this time, knocking Gallade back and backflipping head-over-heels.

"We have the best team leader," Zekrom said, categorically.

AN:

I'm not doing the other E4 battles in this detail. Pikachu got a special treat.