Prologue tree: Skating troupe

Celica Ayatsuki Mercury, and Fūko Kurasaki/Sky Raker meet up in the Muad'Dib Desert. They are being watched over by Hakumen, and eventually Terra joins the crew.
C: Celica Ayatsuki Mercury
F: Fūko Kurasaki/Sky Raker
M: Minerva
N: Narrator

The scene opens in the desert, and Fuko is standing by herself.

F: Where am I, we were all sitting in Haru's apartment a minute ago. Did Brain burst activate?

F: But I'm still my normal self, I'm not a web avatar or a duel avatar... What could be going on?

N: Sounds of digging are heard.

Maybe a digging sound plays? I have no idea how Foley works.

F: Is someone over there? Maybe I'll check it out.

The scene blacks out and opens on Minerva by herself

M: *dig dig dig*

F: Hello, what are you doing?

M: ...

N: Minever turns to reguard her showing a pair of legs sticking out of the sand, then resumes digging.

F: Oh no is someone stuck? Let me help you!

The scene fades to black again, and when it fades back in it shows Fuko, Minever, and a slightly worn Celica.

C: Thank you both for freeing me, it was getting cramped in there.

F: No problem, but how'd you even get like that anyway?

C: I was just trying to find my friend when I tripped. I fell headfirst into the sand, which is weird because I don't remember any beaches being around here.

F: I think we were all moved from where we were, as unbelievable as that seems.

C: Oh that makes sense. So we just have to find our way from where we are to where we were and we'll be fine!

F: I'm not sure it'll be that easy.

C: Don't give up, I have a great sense of direction. Follow me!

F: Alright, you seem pretty confident.

The scene fades to black and opens back up on Hakumen.

H: ... They really should be more careful.

The scene pans out to show that Hakumen has defeated a giant sandworm. (Maybe the kind of worms from Tsubasa chronicles as opposed to the ones from Dune as those hold religious significance to the Freman I think???)

Detailed version of Skating Troupe

"This is odd," a lone teenager said outloud. The scene was unfamilar to her. Fuko Kurasaki, sub-commander of Nega Nebulas, and level 8 fighter Sky Raker, also known as "Strong Arm", she covered her face as a mini sand storm started.
Fuko was 16 years old, and she had long brown hair, wearing her school outfit. She was at her younger kouhai's apartment for one of their meetings and everything was going merrily, until she blinked and was somehow transported into this place.
The sandstorm died down as she lowered her hands and saw nothing but sand and cacti, and some random stones buried. It was also hot, as she started sweating. Not the best thing to happen to a teenage girl, though she wasn't vain.
Fuko noticed that her neurolinker was still active in this desert as it showed the temperature, though it didn't know her location. She tried to contact Kuroyukihime, or the others but oddly enough there was no connection.
'This is bad. The neurolinker is automatcally linked to the internet, and though it's giving me basic information of the temprature, I can't reach the others. I wonder how that's possible. Also, how did I was one moment in Harayuki's place, and now in the middle of the dessert? And is this still Japan?
Fuko tried to rationalize the occurance but couldn't think of anything. Even though when it came to Brain Burst, she'd be able to do something but her physical body was in this place. And no app would work in this place. Or would it.
Taking a chance as she had plenty of Burst Points, she said a simple command. "Burst Link!" she cried out. And there was no blue sheen of things looking frozen or slowing down. "This is bad, there's no connection to Brain burst? How is that possible?"
She had to take a couple of breaths to calm down. Fuko wouldn't be able to protect herself or whatnot as she was a normal girl in this extrodinary circumstances. She decided to walk to get out of this blustering heat.
30 mintues past and she came across nothing. Fuko was keeping an eye out for anything that stood out and all she saw is what looked like ruins spread throuhout the area. She even some something slithering in the ground and she didn't want no part of it and went in the other direction.
Without brain burst she'd be a sitting duck and also started wondering if her friends were in this place? She was about to continue to spiral until she saw the most pecuilar thing; a kind of human sized metalic automaton. Fuko had to blink a couple of times as this was unexpected.
Yes, she was from the future with loads of tech that is beyond most of the characters invovled in this story (some more than others) but even humanoid machines is a stretch, and this one she saw was tall and had a silver metallic shine to it and appeared female.
Getting a closer look, Fuko saw that the humanoid machine was using it's long limbs to move the sand away from someone. She noted two petite legs sticking out the dune. Seeing she needed to help, Fuko sprinted toward the strange scene carefully.
The machine turned toward the girl and stared for a few seconds.
'This is akward,' Fuko thought almost squirming. 'It doesn't even have a mouth. Does it talk?'
The machine motioned with it's long arms to move the sand off the person. Somehow, Fuko was able to get that and helped.
Some moments later, a girl with a pony-tail, wearing what appeared to be a magician's getup for the female gender, coughed out some sand.
"Thank you Minerva, you are so sweet!" the girl praised her companion. Minvera turned to her and as if saying something, Celica smiled.
"As well thank you for helping me!" Celica offered out to Fuko with a smile. Fuko had to process this entire deal in front of her but she being the polite sempai she was, gave a bow.
"You're quite welcome." Fuko said as she waved her hand in front of her face.
"My name is Celica Mercury!" the bright girl introduced herself. "This is Minerva; she looks out for me!"
As if that made this easy to process, Fuko went along with it. "My name is Fuko Kurasaki. And I appear to be lost."
"You are? The same thing for me! I was with Ragna a few moments ago but then I was here in this gigantic desert," Celica explained. "And I was behind him and everything. Not sure how it happened."
Upon hearing that Fuko responded. "Same with me. I was with my friends, and the next moment I was here," She took another glance around her before continuing. "I have no connection to the wi-fi in this area, which is probmatic."
"Wi-Fi?" Celica asked confused.
"Yes, wi-fi. You know, the internet connection?" Fuko replied giving a frown.
Celica thought for a moment. "I don't mean to be rude, Fuko, can you tell me where you are from?

Fuko didn't want to give a stranger any info but the girl seemed harmless enough, though the machine, Minerva, didn't take her unblinking eyes off her. It creeped her out. "Well, I'm from Japan, and-"
"You're from Japan?!" Celica cried out.
"Yes. Aren't you from Japan as well?" Fuko blinked.
"Well, yes but...tell me, have you heard of a place called Kagutsuchi??"
"Kagutsuchi? No, this is the first I'm hearing of a place like that. Is that some hangout you go to?"
Celica thought for a moment longer before hitting with a revelation that was sharper than any truth bullet in Danganronpa. "Fuko, I think we aren't from the same reality. In fact, we might have been sent to another world!"
Fuko was taken aback upon hearing this.

XXXX

Celica, Fuko, and Minerva were able to find shade under a delaptiated ruin, after what Celica said. Fuko had to process the fact of alternate worlds in a literal sense, and not just a game that speeds up the sprectrum of the mind (Brain Burst).
Celica talked about her world and some of the stuff that was a usual deal; ars magus, a scary monster called the Black Beast, and about Ragna the Bloodedge. The tailed-girl also explained how she knows magic and can heal anyone. This set Fuko aback as she's meeting an actual person with magic.
"This is a lot to take in, Celica." Fuko replied after she finished talking. "I have to believe since you healed me of my fatigue,"
Celica nodded, understanding it was a lot to take in.
Fuko looked contemplative for a few seconds before she decided something. "Since you told me about you, I should do the same."
Soon, Fuko explained about the world she's from and about the game Brain Burst. Celica was amazed about the world Fuko was from; a secret game that mostly kids and teenagers know about. Fuko also told her about avatars and some of the lore (which is a lot and I'm not typing it) but she did tell her about her group Nega Nebulas.
This was a forbidden deal of course, but due to the circumstances, this was a freebie and it's not like she was in her world where she knew anyone.
"Wow, so you go by Sky Raker, that sounds cool!" Celica replied smiling.
"It is but I can't seem to do brain burst like that. I'm not sure if I'll be much help in this place." Fuko answered uneasily. "I'm a normal girl with no extrodianary powers and-!"
Minerva soon was in front of them and blocked a large figure from hurting them. To the surprise of the teens, stood a giant worm with sharp teeth. It was a Sandworm and this monstroicty is from Dune. Yes, Dune, that book turned film twice, and made it big in the box office and now a generation will try to use "The Voice" for fun.
Standing transfixed, Minerva went to attack in with her limber but strong arms and sharp claws on her hands. Celica yelled out encourgmenet to her partner while Fuko gripped her hands.
'This is bad, an enemy is here and I can't do anything!' she lamnted. If she could only transform! But this wasn't a game on an app! This was reality. What could she do? She closed her eyes and tightened her fist until her neurolinker glowed brightly.
"Huh, Fuko, you're device is glowing?" Celica said eyes widening.
Fuko nodded as a screen that she could only see popped up and said a simple sentence. "Do you want to use Brain Burst? Yes/No?"
She didn't hestitate as she clicked yes, and soon the bluish light enveloped her. She knew what to say.
"BURST LINK!!" Fuko yelled. Soon she was encased in an oval sphere before appearing in her Brain Burst form, Sky Raker. She was a sky blue colored humanoid alloy with long white hair, high-heeled boots, and nice but deadly legs. Sky Raker was amazed she wasn't in her wheelchair but didn't worry about it.
"Wow, Fuko, you look amazing!!" Celica said smiling brightly.
"It's Sky Raker in this form, Celica," Sky Raker said with a smile in her voice. "I'm going to help Minerva, you stay here!"
"Okay, good luck!" Celica offered out. With a nod, Sky Raker blitzed toward the battle.

What happens next was a lot of flash, blood, and even a cry of "Wind Veil". Before Celica knew it, the sandworm lie dead on the ground, with Sky Raker and Minerva landing on the ground, ala superhero style and even an explosion for dramatic effect.
Celica ate that up and applauded.
Soon, Sky Raker was able to turn back to her human form after the fight. The teen soon noted that she would be able to use brain burst in this world. Though how was that possible? Could it be this world offering a boom to some that are extrodinary to keep that consistency in this reality?
Soon, the duo would continue to walk for a few moments before a guy on what appeared to be a hoverbike speed towards them. He comes down and sees the dead sandworm and asks what the hay happened.
Fuko remained skepetical over the guy but Celica, being able to go by intuition, talked to him like an old friend and there would be no fights between them. This was Terra and he explains the keyblade deal and how he was from another world, ironically since he has traveled to different worlds in his reality but not this one as it isn't linked to his reality (Kingdom Hearts is weird).
He offers to go with them to a city he saw awhile ago; Terra decided to look for anyone in this dessert due to people coming into this world randomly and needed some order. Though not everyone has abilities since some of the populace were "normal" people and not the special snowflakes that have powers, abilities, and whatnot.
And soon (yes, another soon), they would bump into someone that Celica knew, who just so happened to be on the outskirts of this city, soon be named Neo Tokyo.
"Ragna!!!" Celica cries as she saw the spiky haired edgelord.
"Celica, you're here too?" Ragna replied surprised at seeing the eternally lost girl.
"Dark One, you have arrived!" another voice called out.
Fuko, Terra, Celica, and a groaning Ragna, looked to the yonder and saw a white armord individual that looked like an ancient Japanese Samurai.
What could this mean for Ragna?
That will be in a prolouge or just referenced, or a side story. Until then...
BURST OUT!