"This must be the place. This is where one of the small rifts is being detected..."

Yuujin Zone Presents...

"Well, what does that have to do with the Master Emerald going missing?"

A Crossover Fanfic Based on Two Game Series...

"I don't know yet but I'm sure it might be related to this anomaly."

"What do you think Sonic? What should we do next?"

The red sneakers of the blue hedgehog enter the scene as he takes a few steps forward observing the forest he, Tails and Knuckles are in at the moment. Though Mushroom Hill seems to be the same like it is during the Death Egg Incident, closer inspection reveals that the forest itself is a little dim and gloomy as if the leaves are partially obscuring the sunlight. Sonic's eyes open after apparently thinking on his decision, as the familiar forms of the blue hedgehog, two-tailed fox and red echidna is revealed to the non-existent camera.

With a smile, Sonic delivers in his trademark cocky tone, revealing a grin befitting for the hedgehog with an attitude.

A high-speed action awaits Sonic and his friends once more...

"The same like we always do: blast through the place like no tomorrow and destroy some robots!"

The next scene shows Sonic running through Mushroom Hill, the momentum from rolling down the slope helping him achieve high speed. He's next shown attacking Dragonflies with his Homing Attack and then grinding inside an underground cave. After that, Tails is shown posing while flying with his twin tail first before the next scene shows him drifting around a tight turn while running at high speed, attacking the Butterdroids next with his tails and Arm Cannon. Knuckles is shown last swinging his right arm before he punches RhinoBot without mercy before digging underground and then coming out from underneath one with a mighty uppercut. He takes the opportunity to pose in his own way.

However, speed won't be enough for this crisis...

"Reimu? Is that you?"

"Huh? Sonic? You're actually real?" A girl dress in a red and white clothing addresses the hedgehog walking towards her, confusion, surprise and relief etched on her face as well as his.

"'Course I'm real. What? Did the dream we have convinced you that I'm not real?"

"Well..."

Scratching her head while Marisa and Alice watches behind her, Reimu's brown eyes bore down on Sonic's green eyes, somewhat glad they have met for a proper time.

An intense danmaku action is in the hands of Reimu and many youkais...

"If it wasn't, then I'm convinced fate may have set us up to meet there. In that place..."

The next time Reimu is seen, she's shooting out ofudas, needles and danmakus at the hostile fairies shooting out danmakus as well in a pattern, as if it tries to pressure her until she gets hit by one of the orbs. The miko expertly weaves through narrow gaps with grace and carefulness, grazing some of them as she disposes all the fairies on-screen. While she's above Forest of Magic, Marisa chose to fly through the gloomy forest with reckless abandon, shooting out stars, lasers and magic missiles at the fairies and enemy yin-yang orbs. She's doing it in every angle conceivable, from her rear to her front and to her side.

"Have some of this! MASTER...SPARK!"

The rainbow-colored, megaton laser ends the scene with impunity before it transitions to Alice setting up dolls before, as the fairies close in on her with their danmaku shooting, she commands all of them to attack, either through their tiny swords, danmakus, or even exploding upon latching some of them. With her strategic planning, she eliminates the enemy, with Shanghai floating next to the smug Alice.

But, even then, both of them are not powerful enough on their own...

"The boundary between order and chaos has been damaged, which it creates a phenomenon where two worlds are able to go both worlds if specific conditions are met," Yukari's elegant form is shown before the other six standing in attention to her as she continues explaining the predicament they're in. "...while at the same, the space-time continuum like that fox said is disrupted, which may bring catastrophic consequences if left untended."

"So, what should we do next? How can we fix the boundary and prevent a disaster from happening Yukari?" Reimu asks, not liking the way the incident is going.

"We need seven Chaos Emeralds," Tikal reveals, taking two steps forward to the six. "...If we can collect all of the emeralds, then we can fix the boundary with its energy. It may even call upon the Master Emerald, which has been missing from Angel Island."

"To this end," Yukari speaks up next. "We need the cooperation of everyone involved. Whether they like it or not, the safety of our worlds hangs in balance if we don't call upon some friends and allies willing to cooperate together..."

"Did I make that clear, you two?"

Turning to Sonic and Reimu, she expects the answer to be yes, which it is.

"If I have to stop the incident, then any help is needed," Reimu nods, being committed to her duty.

"I've already answered before the proposal is asked. Teamwork is where it's at in this adventure." Sonic replies, flicking his nose with his thumb.

For this adventure, both speed and danmaku collide to make an exciting combination...

In the same area like Mushroom Hill and Forest of Magic, Sonic and Reimu are seen speeding through the stage together, the latter even barely catching up with him even if he's slowing down for her sake. After going through loops, flung by springs, jump from platform to platform and running across Dash Panels leading them to an appropriate route, all with the action expected for the Sonic stage, the next section shows Reimu firing danmakus against the fairies and flying Badniks, with Sonic riding on top of her like an Extreme Gear occasionally defeating some of them with his Homing Attack and ducking and swerving when the enemies attack. Despite the different way the hedgehog and miko do things, the two are already working in tandem with each other, complimenting their strengths and covering their weaknesses.

"A perfect response! I hope that whoever you meet along the journey," As Tikal speaks, recognizable characters are seen in the screen for a brief moment, starting with Tails, Youmu and Yuyuko standing on a snowy cliff. "...Even if there's some differences between us," Suika commanding Knuckles to attack, much to his amusement in a snowy landscape and Marisa, Alice and Amy looking at what's ahead late at night, "...My sincere hope is that we can all enjoy our company and, if possible, become friends or at least acquaintances." The final brief shots are of Shadow catching Sakuya's arm as she moves in for the kill, Omega encountering Flandre in the middle of the mist, Reisen scratching her head while laughing awkwardly before Cream and Cheese, Charmy holding an uprooted sunflower while Yuuka is towering behind him, and Kokoro's first meeting with Espio.

"Being friends with a blue hedgehog? That's gonna be a new one."

"Hey, be positive. This cooperation will surely be a memorable one."

The last scene is Reimu and Sonic initiating their Team Blast, comprising of Sonic, in his ball form, repeatedly being batted by Reimu using her gohei stick before finishing it with an Ascension Kick that propels Sonic up in the air before dropping on the ground with Boost-infused Stomp, creating a shockwave. Then, the title logo is shown, with Sonic and Reimu saying the words separately.

Sonic X Touhou: Phantasmic Entropy

"Huh? We're alive? I thought we might have been perished in that explosion back there." Sonic says, surprised and looking at himself to make sure he's, well, alive.

"Huh? Who's that?" Reimu inquires, having not turn to him as she's staring at someone in front of the two.

"Hmm?" Following her line of sight, Sonic sees a monochrome boy holding a gray Chaos Emerald with one hand, seemingly fixated at it until his red eye stares at the two and possibly the screen as well.

Sonic: Alright! The first trailer is here! Man reading this surely decreases my patience for its release! I guarantee that this will be a good one and hope the author is now keen in finishing it and doesn't cancel it.

Koishi: Oniichan? Why are you so- Hm? What's this? *gasp* Is this the trailer for Phantasmic Entropy?

Sonic: Yup. Somewhat figure the title may not change. It sounds perfect.

Koishi: *after reading it* Wow! This is awesome~! But I don't see myself appear here.

Sonic: Relax Koishi. There's still two more trailers before the author publish the crossover. Who knows? Maybe you get an appearance, even if it's only brief.

Koishi: Y'know, I'm kinda jealous that you get more screentime because of you being the protagonist. I wish I was a main character!

Sonic: What? Being popular with many fans including the author isn't enough for you?

Koishi: Well, no. But still... Bah, who cares~? Ignore my complaint. Now, I wonder what's the second trailer is gonna be like? And who's that guy at the end?

Sonic: Oh, you mean the OC?

Koishi: Yeah. Who is he?

Sonic: ...Original the Character.

Koishi: ...That's not his name, isn't it?

Sonic: No. Just be patient for the next trailers. Who knows if character is revealed in more detail, either in the second trailer or in his character trailer.

Koishi: The latter seems likely. But either way, I can't wait~ Hope the author isn't procrastinating~

Sonic: He wasn't. He's still got a life, you know?

Koishi: Heheh. Right... Anyway, see you all next trailer~!

Sonic: Take care everyone!