Spoilers from included and/or represented works abound. Please read this fiction carefully.
"Everyone!" David took the Akasha Terminal to warn the alliance. "The Sideways have been directly unleashed, all corrupted monsters just got stronger!"
The war continues, with the brutal clashes and decapitation of corrupted monsters going on. However, Genjitsu-no-Omnia caught the Herald (who transformed into the magical girl) from afar.
"What's with you, the magical herald!?" Omnia is enraged. "You joined the ranks of those lowly resistances!?"
"I never volunteered for you, I spied you and your servants." The Herald revealed. "I am your mole, and I knew what you're up to. Also, you must have had Chromed the Collider yourself."
"How could you figure it out!?" Omnia is distraught about it. "No... those lowlifes should've been adrift by now! You just exploited the island!"
"But at the very least, the Queen of yours accelerated my plan." Omnia subverted herself. "You're a mole, so I don't spare you anymore. Begone-"
The Cube Queen crashed to Omnia, saving the Herald.
"Leave my people and my children alone!" The Queen, dining the Seven Agent suit of her design (again, the sleek futuristic version of normal attire with elements of Origin's armor and the Herald, but has blue palms).
"The Queen! Are you alright?" The Herald floats to the Queen.
"I've got a new Seven armor, thanks to some crystal ball!" The Queen handwaved. *looks at Genjitsu-no-Omnia* "You are so irresponsible, you caused problems! That's why I decided to exile you and strip you of your titles!"
"Ugh... That's why?" Omnia heard it. "My queen, as screwy as ever."
"Then after the exile, you got fed up with the island's folly and decided to crave the path that make you insane gaining just to gain powers!" The Queen called out Omnia. *collapses visor* "I should have disciplined you in the first place before all that. Or after the problems you caused, I should have killed you!"
The Queen fired a corrupted lightning beam onto Genjitsu-no-Omnia at point blank. The latter shrugs it off.
"The Nothing is broken, because you took revenge onto both the island and our horizon at all once!" The Herald summoned Chrome fireball to Omnia.
It isn't very effective...
"A mole of mine, and her queen previously mine. A queen and her herald. Both stupid outdated higher-ups, opposing me over king's folly." Genjitsu-no-Omnia mocked both. *activates Mantis Blade, causing Margueritte Bois de Justice* "Time to execute the old queen and the mole!"
A rocket, the same type of rocket Seven'd make, and the same type used to help restore Reality Zero, suddenly interrupted, flying towards Omnia. She simply floated there and sliced the rocket in half. It exploded afterwards.
"You suck, defected Goddess of the Rifts!" The Herald then spit out the Chrome with her hand, sticking it to the Mantis Blade.
Both Last Reality great figures escaped, while Genjitsu-no-Omnia retracted the Mantis Blade and struggled to control the Chrome the Herald spread on, forcing her to tear it off.
"Damn it! That Chrome isn't the same!" Omnia threw it randomly.
The Chrome threw off splattered Jason Voorhees (one of the survivors fighting to save the reality), chromifying the serial killer. Using the Chrome abilities alongside his own horror-full killing skill, Jason wreaked havoc against the corrupted monsters, saving various soldiers and warriors and players and helping them destroy this monsters.
Shortly thereafter, David met Jason. The Chrome wears off, and the serial killer collapses.
"Wow, somehow he got chromed. Wait..." David is confused. "Chrome? Cyberpunk conversion or that substance?"
Agent Jones appears behind David, is about to tell him something.
"Mecha Team Leader... Mecha Strike Commander... And now, on the island-ship!" Agent Jones reported.
"Huh? I thought you don't use it anymore?" David is confused.
"I'll tell the Seven, the IO, and those from of the Last Reality." Agent Jones then ran away. "Tell your friends about the mecha!"
"Huh? Why there's that island?" Genjitsu-no-Omnia noticed Beyond the Edge. "Crap! Last Reality, attack it!"
A few Motherships and several Abductors approached the island-ship. However, in the middle of the island-ship, a rebooted Cube appeared (glowing blue), creating a protective shield (the similar design as the Storm) on top of the current shields, to protect the ship. Some of the alliance noticed that...
"Wait... I thought that Cube is no more!" Peely recognized.
"The Rebooted Cube... What, it returned!?" Mecha Strike Sentinel noticed.
"How strange it is, but let's fly to the ship!" Mecha Strike Sentry continued.
"What!? That damn defective!" Omnia is frustrated. "Destroy it and attack the island!"
Abductors charged ahead, but the island-ship, thanks to the power of the Reboot Cube (nicknamed Blevin), struck them down with lightning. Motherships slowly approached, but the Ultras returned to normal sizes and destroyed them.
"Those annoying motherships is 20,000 years too early to breakthrough!" Ultraman Zero as Ultimate Shining Zero.
"Not those Ultramen again!" Genjitsu-no-Omnia commanded more Motherships, and thousands more Abductors against the island-ship.
"Everyone... go!" Ultraman Reiga charged.
On the side currently facing up, there's the Mecha Team Leader... uh... Mecha Strike Commander, idling in the construction and maintenance, heavily damaged.
"Here it is, the Mecha!" They arrived.
"The mecha we once used. Or twice, depending on who." The Foundation recognized.
"What? You plan to use a robot?" Geno isn't amused. "But we have a doomsday device!"
"Actually, it has been destroyed." The Paradigm noted. "Originally, we destroyed it with the help of that mecha. And earlier today, the device exploded, corrupting the ocean after the re-flip."
"Why do I have to stop you?" Geno is frustrated.
"Actually, we're here to fix the mecha, upgrade it, and recommission-" Agent Jones explained.
"Yeah yeah, we have to put mecha back in action." The Foundation noted.
"But the problem is..." The Paradigm replied. "It takes days to construct! And it only have been hours of this war right now!"
"That's why I have the new gadget, powered by the combination of Zero Shard and Kiramai imagination." The Scientist showed the gadget.
"That one gave me... my armor?" The Queen noted. "You want to use it to speed up the construction?"
"That's the only safe way around it!" Agent Jones replied.
"Agent Jones, speed the construction up so we can do fast enough." Sentry suggested.
"And I'm suggesting to bring the old arm, as well as rebuild the device as a bonus." Agent Jones suggested.
"The union of the Imagined Order, the Seven, the Resistance, and the Last Reality." Sentinel suggested. "Make that mecha-"
"Yeah yeah... Speed!" Agent Jones activated...
The entire side of the island-ship sped up, slowing time around the group and the construction.
"Now we can start constructing." Ariana Grande responded. "Start construction!"
And so, the group started. First up, they fixed the mecha. Then, they took their design ideas and upgraded the Mecha based on it. And finally, reconnect, and controls...
Meanwhile...
"What? What... happened?" Strange Supreme woke up.
"I did it! You're back!" Soren replied.
Strange Supreme got up, and realized the atmosphere is getting worse and worse. The protection is wearing off, so Supreme refreshed it.
"I can't cast more right now. I need some rest." Supreme is still exhausted.
"I'll help." Earth-616 Stephen Strange assisted.
Earth-616 Spider-Man (Peter Parker) and Earth-616 Iron Man (Tony Stark) both appeared in their Zero suits, also. Monster clone of MCU-616 (Earth-199999) Spider-Man (Peter Parker) ambused.
Note: Why monster MCU-616/Earth-199999 Spider-Man? Because the 'forget' spell in No Way Home actually erased memories of who Peter Parker is.
"Hey, alter-Spidey!" Earth-616 Spider-Man taunted. "Try and take us!"
Meanwhile, the dozen of Motherships and thousands of Abductors is still attacking the island-ship, but it's protected by the rebooted Cube and the Ultras. A few minutes in real time, the construction is finished, and the Mecha is back.
This Mecha has a new paint job: silver torso with No Sweat Insurance logo pasted in random (representing the Resistance), left arm in white and gold (representing the Imagined Order), blackened right arm, and bright blue legs (representing the Seven). It's empowered by Imagine Breaker (on right arm) and its extensions, a Golden Cube and the Zero Shard, and the old arm are reengineered as the holder of the Sword of Singularity (taken from the Tilted Ruins and Gunbuster), armors covered by Cube runes (representing the Last Reality), and Chromed joints and head (representing the Morning, and by extension, the Last Reality). Its left arm, in particular, is clearly a miniature version of the Collider attached with the existing left arm (representing the Imagined Order). It's co-powered by said golden Cube (rebooted, and representing the Last Reality) and the Zero Shard (simultaneously representing the Seven, the Resistance, and the Imagined Order).
"Here be dragons!" Agent Jones entered the cockpit. "Legendary battle mech, evolved!"
"Can manipulate and bound the realities all one want!" The Queen declared.
"The mecha's back." The Foundation operates. "It's up to us to act. Paradigm and Queen, pilot!"
Commissioning Paradigm and Queen to co-pilot the Mecha, while the rest of the group operates the things.
"We call it..." Agent Jones announced. "Mecha Fusion Overlord!"
"Miss Paradigm, the mecha is back, I'll be the mission control." Singularity (Imagined Order) appeared on the interface.
"Singularity of the Imagined Order?" The Scientist noticed.
"It's you, Singularity." The Paradigm recognized.
Cross-trivia: Contrary to the previous hints as provided by the popular Fortnite theory, Paradigm isn't Singularity; or at least, the current Paradigm we got (from Reality-659, based on Brie Larson) isn't Singularity. Said theory being disproven by Zero War writer on Twitter on August 22nd, 2022.
Note: *read that Cross-trivia above* That's is why I deliberately left out the exact identity of Paradigm for all her appearances in this fiction until just about that point... above. (And no, that Singularity isn't the same as the final boss using that name (already killed off in both Bayonetta 3 and earlier in this fiction), so... duh.)
"I'm stuck out of time, and I'm glitch in my existence, after all that happened so far..." Singularity explained. "You have to save the reality!"
"At this moment, you need to leave this ship you're standing in and intercept that messed up island, now!" Singularity gave the mission.
"On it." The group crewing the Mecha.
Mecha Fusion Overlord. It did 'No Sweat' pose, left the construction, and ran out of the island-ship. It jumped, and the Chrome joint bounces, leading to greater leaping length and height.
The alliance noticed the Mecha, and rejoiced.
"The Mecha came to rescue!!!" Hoshimatsu is shocked seeing it coming.
The Mecha lands in style, crushing a horde of corrupted monsters. Then it crushes some corrupted monsters just by running. One such monster as Delusional Orange quickly transformed into a gigantic Dark Orange, but is kicked away by the Mecha, crashing to the Pyramid.
"Oh, hey! Hello mech!" The Ultras greeted.
"What the rift is this!?" Genjitsu-no-Omnia is pissed off.
"Look! It's that Mecha!" David noticed.
"Mecha Team Leader evolved again?" System No. XX is surprised.
"Yay!" The Sephira rejoiced.
The Mecha then sided at Omnia, and...
"Fuck you, the treacherous bad girl!" The crew has the Mecha flip off Omnia with its left hand.
This enraged Omnia, and she summoned 22 giant clones of the frosted Devourer to attack the Mecha. They were stylishly destroyed by the Mecha, however, as after pulling the sword, swings off each differently, and finally enough time to pose like a badass.
"This is much better!" The Paradigm is excited. "We could do it all day!"
"Zero Break!" Geno clocked it up.
Using the miniature Collider with the power of the original, the Mecha throws a lightning ball of yellow and blue, into the crumbling Pyramid, destroying it.
"What're you doing!? You're starting to disrupt-" Genjitsu-no-Omnia gets raged up.
"Your ridiculous goal?" Singularity mocked Omnia. "We've got no sweat."
Omnia teleported away. All the remaining corrupted monsters and Abductors and the last of Motherships brought up are all destroyed.
"This is it. This is the last one." Angela reported.
"All this monster taking forms of lost existence, all destroyed." Saya saluted. "Mission complete-"
"Where's Byaku Shin!?" Frank West asked everyone. "Where's Kyuju Kyu!?"
The island shakes again. The sky cracks with rifts. The merger is almost complete.
"Everyone! Brace yourself!" Ms. Continuum and Singularity all warned.
The entire alliance gathers to the center, and all around the bouncy remains of the Pyramid and thus Eye Land.
Suddenly, the island is shattered. Zero Point exploded once again, knocking the entire alliance away and up. This means the Zero Point has crashed, and the Reality Zero has been merged with the Last Reality.
The entire alliance then falls down. However, the island-ship flew and rebooted its atmosphere, allowing for survival, which everyone up Greek through. This saved the alliance from falling to death. The Mecha lands in style... again.
"I thought we're dead now!" Various complained after they just (finally) got up.
"The island is shattered. Zero Point exploded again. The atmosphere becomes the Last Reality." Jeanie noticed. "This indicates the Reality Zero has been merged with the Last Reality."
The inhabitants of the Last Reality gasped at the sight.
"My people!" The Queen noticed. "Oh, so... my realm merged with whatever contained the island?"
"Yeah, that happened." Singularity replied. "The Reality Zero has just been merged with the Last Reality. At least we all survived."
The island-ship then flips, allowing the alliance to see the Zero Point upwards from the upside-down point.
"The Zero Point... It's stressed out, and can go haywire anytime!" Kogoro noticed.
"Wait... no more sign of vitality on the rebooted Cube in the epicentre." The Scientist realized. "Does that mean... it's destroyed? Again?"
"Yes." Dr. Manhattan teleported to the cockpit. "I just check it. It's destroyed, only fragments remaining, just like during the original invasion."