Spoilers from included and/or represented works abound. Please read this fiction carefully.
"I can't believe it... All of the remain Shadows fused into the rogue ghost!" The hedgehog is in disbelief. "And look!"
A footage of Nimona impersonating Reinhard Tristan Eugen Heydrich and using the Prismatic Zapotron to fuse Agent Phantom, Savage and Jones with Ghost Shadow, reviving Prime!Shadow.
"How dare you... Gestapo impostor!" The hedgehog yelled. "Who are you, that impostor!?"
"That Mephistopheles... No, they're still in the bunks, infected by Metal Virus!" Miles pointed it out.
"Exactly!" The hedgehog punched the screen, breaking the whole computer.
"Look at the footage! There's strange red strands in what should be glowing blonde." Miles pointed it out (again). "Does anything has the... uh... those kind of strands of... let me see..."
The footage changed mode, now showing power signatures of each and everyone. Nimona's signature stood out.
"That impostor has unique signature, showing they're from yet another world plucked into unified world." Miles noted. "Do anyone have seen..."
"Nimona?" Nightmare Rose came by, shocking the two. "Wait... oh, the footage! Color-matchs my memory!"
Turns out, over a week ago, Nimona ran for the database that allows her to know how to transform into figures such as Reinhard. Unfortunately, Nightmare Rose was tending Cyber Dream, and picked up the power signature from the shapeshifter. Nimona never noticed, and only by day 10 did the shapeshifter get the database; she failed to account for false Amy, who memorized the signature.
"That's it! Her name is Nimona! I just so happened to see her running over a week ago!" Nightmare Rose pointed it out.
"Amy! Thank you so much!" The hedgehog got it. "That one... she did it... AAARGH!"
After the dinner, Sonic got Nimona the comics, allowing her to better get known to the veterans.
"Oh hoy!" Time to sleep!" Marine fell down, sleepy.
Just in time for Nightmare Apoptosis - Ariem attached into Guardian Hunter - to attach the entire unified army and Dreamweaver, causing everyone to fall down to Cyber Dream.
"Uh..." Sonic got up in the ruins of the Reverie. "This... is Reverie? What's exactly..."
Ariem roars in the background, echoing the entire area.
"What's going on!?" Sukuna? Huh?
"Hey! Wait..." Sonic noticed. "There's two of y-no, four!?"
It was the four Naraka Observers: Zurvan, Judas Strife, Shirou Yusa, and the real Tenma Sukuna. This sent Sonic into a mental loop.
"Wo-wo-woah, calm down, please..." Shirou trying to meditate the other three.
"Seriously!? The fuck-" Zurvan is then interrupted by Judas... then Sonic did the same to both.
"Oh. You finally came. Varhram's messy right now. We're split." Sukuna called. "We're not the only one. But then again... let me say this case: we're Sensories of Naraka. We're the Observers."
All four have supreme marksmanship, something Sonic recognized from the 'fused' Sukuna. And apparently, Ellie Strife, because...
"Ellie! You're late to the case!" Shirou called.
"Shirou... this maze's... screwed!" Ellie, with a sword in her hand.
"Thanks you for meeting up. My name is Sonic the Hedgehog." The Blue Blue then rushed out.
The five nodded, albeit somewhat reluctantly in Zurvan's case, and all six went through the ruins.
The rush shows that the Reverie, after fusing with the Cyber Space and other dream worlds to become Cyber Dream, has crumbled from sheer instability and fusion, and further fallen into shambles by Ariem's corruption.
"This place's out of sync, at the very least." Judas commented.
"Mr. Apoptosis, you're right." Sonic nodded. "This place's already crumbling. I bet this is the deeper layer of the Cyber Dream."
"Ravaged by the glitch..." Ellie jumped, while looking around. "I know those glitches corrupt. I've been a hacker in a previous life."
"Ok, bitch, good observe-" Zurvan is verbally interrupted by Judas.
"Seriously?" Judas sighed.
"Fine!" Zurvan groaned. "Let's keep going around this broken place!"
Soon enough, they found the rest of the unified army, in weirded chaos because... Tai-Aztiluth has split.
"They've all been split into components!" Sonic jumped in. "Guys! Calm down!"
"Sonic, I'm afraid two voids will backfire!" Amy called.
"The confusion is because all have been split into their components!" Knuckles then saw the Observers and Ellie... "Oh no! You have one of the worst splittings out there!"
"Isaak Heydrich, the slow-age... holy crap, the puns' messed up!" Classic Vector scrambled through Isaak, the Sonnenkind himself.
"So wait... you were all components, forcibly fused for some reason?" Sonic is confused. "Is that what Mr. Yato meant when he said he knows what you are by then?"
"I gotta admit... I know the truth now." Rusalka Schwagerin, the Malleus herself. "Indeed, the torture dumped us into and unto ourselves, and got us suffering! We could still use our powers so long the loser state isn't triggered, but still!"
"This is not Pantheon, this is an outright glitch!" Nicole revealed what's up with the split. "And yes... I can confirm Mr. Yato himself."
Ariem roared again.
"Oh no! We're dealing with the corrupted Dreamweaver also!" Sonic realized.
A shadow of Guardian Hunter - actually Nightmare Apoptosis - appeared at the ground. Sonic recognized the shadow, just vaguely.
"Guardian Hunter again!?" Sonic realized.
"Look! Over there!" Tails pointed up.
The creature landed down, quaking the entire area.
"Ariem!" Sonic is horrified.
"Oh no..." Amy stepped back.
"How dare they..." Knuckles growls. "Ugly returns..."
Ariem roared, shaking the entire area.
"Oh my god. Time to clean up the dreams!" The teams then rushed off.
The creature instead of shooting spikes ball like it did in the past, now shoots raining meteors instead, akin to Satanael's. Habaki was able to vaguely recognize it, but had to dodge before he can speak up.
"This one's spewing meteorites!" The Robot Masters on the run.
The Heroes of Tomorrow found a bunch of literal building materials and a magical blueprint, while the Classic ones sped up to escape the rain; they're blocked by a... storm circle.
"What's this!?" Classic Tails stopped.
Trip went into the storm, and suddenly writhes in agony. Classic Sonic had to pull the stargazer out.
"And it circles inside and shrinks around this battlefield!" The Classic Chaotix then went back. "Run back!"
The gods are even struggling against the creature, showing the corruption of the Dreamweaver are clearly paying off: after all, she can make dreams into reality with her powers literally.
"Yeah yeah yeah..." Infinite is frustrated. "The Dreamweaver is so powerful, no wonder why even gods are struggling. The twisted environment doesn't help."
Standing in the storm afar, Nightmare Rose is drinking the dream serum, sipping through like a tea. The sadistic and false Amy Rose watches the fight unfolds. And the Nightmare Apoptosis finally moved after taking a few dozens of hits, making harder.
"No choice but to strike against it directly!" Sonic, imbued by Speed Force, Spin Dash the creature. "Ariem! We'll save you!"
Ariem roared, as she computes the behaviors of the creature against her will. The Heroes of Tomorrow stumbles around the nigh-homogenous builds connected to each other and framed for any extra openings, all which and the meteors destroying said builds got noticed them. Deja Vu indeed.
"Hmmm..." Ryu approached them.
"Uh... Do you know how to use this?" Kiryu asked.
Suddenly, Ryu fully remembered his time at Reality Zero. It's like Nicole returning the memories, but it's... multiversal across the board. Some of the other World Warriors came by to see the blueprint and creation, but ended up getting the same kinds of memories.
"What the...!"
Meanwhile, the storm shrinks. Everyone had to get inside and escape the storm's way, which lead to the meteor rain that's trying to kill everyone. Unfortunately, this meant everyone had to fight Nightmare Apoptosis. Worse still: in the waking world, they've all been caught by the creature herself.
"GRRRRRHHH!" Ariem roared.
"Ariem! What should we do!?"
A meteor falls onto the Blue Blur, and while he could just dodge, he is desperate to get Ariem off and save her.
"Sonic, watch out!" Merlina yelled.
Sonic listened in shock, and managed to barely avoid the meteor. However, there's a few more meteors falling down to the area. *booms* A chunk of materials fell down in pieces.
"Huh?" Sonic looked up. "Wow, what?"
"Shoryuken!" Ryu uppercuts the creature, nearly knocking it down.
"Well, well, well, the transistion from indirect Zero Build to-" Chun-Li then saw Sonic, while kicking off some wood. "Sonic, what are you doing?"
"Wait... you built something to protect me." Sonic figured it out. "Oh, that's it! We can protect the weak by building!"
"Oh, really?" Rusalka heard it.
"We have materials! A ton of materials that we just finally figured out how to use!" Ichiban yelled. "C'mon! Take this, and see for yourself!"
The creature noticed what the unified army just learned, and roared in rage.
"Admit it! We're outsmarting you!" Tails declared. "Sonic, guys! Let me figure it out! Just give me them!"
"Very well..." The Heroes of Tomorrow outright gave Tails the build mode. "We hope this works..."
Tails, the genius that he is, while the Eggmen are busy dealing using their own intellegence, the fox himself examined the builds and materials.
"I uppercutted it, and it almost toppled over." Ryu commented, while blocking the explosions.
Tails heard that, and keep that in mind. The creature easily and flyingly recovered all that the army has thrown so far.
"We need to break its plot armor!" Boom!Sonic yelled. "Her dreams came true already! This is bad!"
"Let's see... Shoryuken to try and topple... the shades of Ms. Malleus and Mother of Distortion, dragging it down... And some more stuffs..." Tails thinking about it. "Which build is the best?"
Ariem roared, and whacked Knight Arthur, knocking his armors off.
"Ultimate Armor! Engage!" X went all out on the creature.
It doesn't work, because X's attacks are just not fast or powerful enough to scratch. The living robot is whacked down, before being subjected to a meteor fall.
"NO!" Kiryu built a box home for X.
The meteor hit the build, destroying the walls.
"Damnit..." X then stepped out.
"Sonic! Hook her power with your speed!" Tails yelled. "Everyone else, come here! We have a plan!"
Ariem just roared again, and kept on attacking. Sonic used Speed Force to Spin Dash the meteors, which actually destroyed them. Leaving a bunch of Dream Orbs, which he never seen since the Reverie incident.
"Oh, that's it!" Sonic got it. "Tails, guys! Keep your plans going! I'll break those meteors!"
Enraged, the creature roared and summoned more meteor rains. Sonic broke all on their way to danger, allowing the unified army to come up with the plan Tails formed. Sonic then also Spin Dashes the creature, but it just recovers immediately.
"I think the plan's the only way!" Sonic evaded.
"Alright..." Mega Man took a build mode, and quick-editted his way with the help of Speed Gear on the creature's back.
Everyone rushes, and the creature is confused because the army split way, further distracting through Sonic destroying the meteors. At this point however, the storm now circles around quite small, and have increased deadliness.
"Magic bullets!" The Observers shot the creature repeatedly, slowing it down and preventing it from summoning its rain.
"SHORYUKEN!" Ryu and Ken both did a joint uppercut, knocking it off.
"Csejte Ungarn Nachtzehrer!"-"Mugen Kokujou Jigoku!"
Both versions of Malleus managed to drag Ariem upside down, toppling the creature altogether. Unable to move anymore, the Nightmare Apoptosis is stuck. At that point, Shirou and Judas just chained from their body to it to restrain, just before said creature got the chance to bounce back up.
"It's over. Now get bursted!" Shirou laughed. "Alright! This is for the Reverie! And for you, Ren too!"
-*magical gunshot*
"AAAAARRRGH!" *explodes*
The explosion caused a glitch wave which erased the storm from the whole area. And then, it subdued, revealing the army surviving all, and the Nightmare Apoptosis limping, defeated and crippled, bleeding Magination.
"Nightmare Fuel bleeding the hell outta her." Habaki sighed.
"Hold my hand." Nicole came by the sides. "Let's fix her. We can save her and free her from the corruption, though she won't be fully restored physically just yet."
"Whatever you say, Madam A.I." Habaki accepted, and held Nicole's free hand.
Nicole hacked the creature, helped by the Dream Orbs lying around from the rain and Habaki's healing. This rebooted the device binding Ariem, purifying her.
"Tails, thank you for the plan you concocted. However, because of firewalls and failsafes, I did the hacking for you." Nicole left Habaki's hand. "Now, she's finally saved. Physically speaking, she's still in monstrous mashed form we're seeing her."
"Let's me modify the Dormancy Protocol..." Tails aided Nicole in the setup. "Here. Now she can have her powers back. She still won't be allowed to directly make dreams come true, still."
"Uhhh..." Ariem woke up. "My... voice..."
"ARIIIEEEEEMMM!" Sonic hugged the actual body of the Dreamweaver.
The unified army celebrated the salvation.
"Sonic... You... you all..." Ariem finally got back. "...saved me..."
"We've all saved you, thanks to clever tricks." Tails responded. "You're back! Finally, welcome!"
"OH MY GOD!" Ariem hugged back in response. "The Dormancy Protocol..."
"I fixed it. Now you don't have to be defenseless again." Tails reassured.
"The Ugly makes way to the actual Dreamweaver." Knuckles laughed. "We did it. We saved the Dreamweaver!"
Her designated body got up, her actual mind cleared and restored. The Dreamweaver then looked at her own body - that of her mutilated original body cybernetically grafted into the front of Guardian Hunter - she's really horrified and disgusted at it. Nightmare Rose saw all this aftermath, and she's pissed.
"My body... desecrated..." Ariem bitterly commented. "What the... Urgh!"
"Don't worry, you have us." Sonic reassured.
Nightmare Rose builds up her anger the longer she learn Ariem's purification, but because it's so late, she didn't bring herself to the army for revenge. She left.
To be continued...