What If Ash was in Pokemon Horizons?

Roy is Crocalor, and Crocalor is Roy!

Heh, HZ069, nice.

The Rising Volt Tacklers arrive in Kitakami, they take a bus through Kitakami Road to Mossui Town, planning to ask around if anyone knows where Briar is. As soon as they arrive, they find the entire town almost completely deserted. A shopkeeper informs them that the townspeople are off enjoying the annual Kitakami Harvest Festival, so the Rising Volt Tacklers decide to head there to both have fun and ask around.

The Rising Volt Tacklers arrive at Kitakami Hall and change into some festive clothing. Ash and Friede find a Sinistcha, which Ash scans with his Pokedex.

Ash: Woah, who's that Pokemon?

Rotom: Sinistcha, The Matcha Pokémon, a Grass and Ghost type.  It pretends to be tea, trying to fool people into drinking it so it can drain their life-force. Its ruse is generally unsuccessful.

They meet its trainer, Carmine. Friede wishes to take a closer look at, but Carmine doesn't trust outsiders, not even The World Monarch. So she challenges Friede to a game at a carnival booth. Friede happily accepts and runs off with Carmine, though Ash figures out that he's just happy to enjoy the festival.

Ash meets up with Liko, Dot and Roy, no one knowing Roy and Crocolure switched bodies. Roy soon finds Crocalor interacting with his friends, and ends up talking to them, forcing him to reveal the truth. 

Roy: Crocolure and I met a guy, he gave us a machine and we swtiched bodies!

Ash: Woah. That is werid, but kinda cool!

Liko: Ash! Really?!

Ash: What? I would wanna be Pikachu for a while. Well, I was a Pikachu.

Liko, Roy & Dot: WHAT?!?!

Ash: It's a long story! My friends and I met some wizard who offered to cast a mind reading spell on me and Pikachu, only for her to turn me into one! But it only lasted a little while though!

Pikachu: Pika!

Roy: Well, what do we do now?

Ash: I say, we keep things on the down low for now.

They're then approached by Murdock, who offers to treat them to anything they like. The kids want to get the situation fixed, but they also want to enjoy the festival, so they accept Murdock's offer, and he leads them to a stand selling syrupy apples. Roy tries to take one, and ends up accidentally spewing fire on it. Murdock, though, sees the combination of caramelized candy and a gently baked apple as a new kind of delicious baked treat. The candy apple seller asks if they could make more of them, but the children politely refuse and excuse themselves.

The kids spot Orla trying to fix a broken stove at a stand. They can't help but get involved. Orla finds herself unable to get the stove to heat up properly. Roy gets an idea, and his friends ask if they could use "Crocalor's" fire to heat up the stove instead. Roy gets into position under the stove, and he shoots out a more powerful flame than intended, sending him flying and requiring Crocalor to catch him. Crocalor cheers, which encourages Roy to give it another go, and they sing their song together, allowing him to produce a proper flame. Ash, Liko and Dot note how Roy and Crocalor make a great team, even in swapped bodies.

The man the kids were looking for finds Roy and tells him that he's managed to get the machine to work again. Roy and Crocalor return to the man's remote stand and use the device again, restoring themselves to their original bodies. Ash, Liko and Dot reveal themselves from a nearby bush, wanting to try out the machine as well. The man agrees, and Liko and Floragato press the buttons together, but nothing happens. When the man examines the machine, it suddenly breaks down, much to his horror. 

Ash: Looks like Clemont's work to me.

Roy: Who?

Ash: A friend of mine. His inventions always broke down like that. But man science is still so amazing!

Dot notices the text "Synchro Machine" written on the back of the device, and the man actually thinks Clemont actually made that machine and starts frantically apologizing to them.

At sunset in Mossui Town, the Rising Volt Tacklers reunite. Carmine shows up enraged that she lost to Friede earlier.

Carmine: You! I demand another game!

Carmine then notices Ash again

Carmine: Nevermind! World Monarch! I want a battle!

Ash: Sorry, Carmine? Was it? But we have to find Briar

Carmine: Well, in that case, Briar is my teacher. And she's at the Crystal Pool, and outsiders can't go there! So I guess you're outta luck!

Suddenly, the caretaker of the local Community Center and his daughter approaches them.

Shizune: There he is dad! The boy who caught me!

Ash: What?

Roy: Oh yeah, Crocolure and I rescued her from a bad fall.

Caretaker: My on my! It's The World Monarch! Well now I know now that you lot deserve a bug thanks! What can I do to repay you?

The Rising Volt Tacklers push Ash to the front to represent them.

Ash: Well... I hope it's not to much of a hassle. But we need to get to the Crystal Pool, but we're not allowed in.

Caretaker: Oh? Is that it? Go on ahead!

While Carmine fumes in frustration, the Rising Volt Tacklers prepare to head for the Crystal Pool.