Spoilers from included and/or represented works abound. Please read this fiction carefully.
"You heartless machine! How could you return!?" Future Rex is infuriated at being caught by Alpha.
"Isn't Singularity taking my mom's form enough already!? Now you are disrupting our paths!" Viola objected.
"I'd say I agree with CXA." Vinicius (Rio 2016) agreed.
"Why?" SCP-239 objected. "Alpha, WHY!?"
"You have the audacity to both undo the salvation and defy me, a god?" Alpha pointed his Monado to the parties. "Especially you, the Lost Numbers?!"
"I barely even knew you, stranger." Kado scoffed at Alpha. "On the other hand, your sword might be in my collection."
"Looks like this Alpha is far worse than the Alpha we used to fight against." Na'el told the rest of the Founders.
"Can't say I'd object you. In fact, I object that machine." Nikol then looked at Future Shulk. "Right? Um, dad or what, mister?"
Two Shulks look at each other in awkwardness.
"I'm afraid you're not getting away with any of this." Alpha denied. "Come... Titans! My godchildren, destroy those rebels and terrorists!"
"How do I open the dome large enough without sacrificing control or tangibility?" Arak/Telos thought.
"Yikes. Zero Cluster is screwed." MEGA!Evie realized.
"A bunch of Titans... the Rumbling! It has come to our Islands!" Kado spotted them, so he scoped to their eyes. "Their eyes are glitching the same way as Tracking Error! Flashing between red capital Omega symbol, and rainbow-holos of the Last Stop's glimmer being unleashed! The glow of Phantom Ruby and the glow of Ultron-Sigma's virus are combined, too! They're infected by the evolved Anti-Life!"
"What? The Titans? Rumbling?" Shinra-Ouma alliance haven't noticed yet.
"I can hear them too." System have. "The Rumbling has come. And bolstered by the Equation, to boot! Even worse, I suspect the evolution is pushing its resistance against the Life Equation!"
"Uh oh. Several thousands of corrupted Titans goes brrrrr...!" Travis wheezed.
"Can't you be perpetually serious at the life-and-death moment?" His daughter Jeane knocked him.
"Jeane, I'm an otaku, so..." Travis shrugged.
Everyone got quickly teleported on the Battle Buses, with some inside and some above, all hovering on the level of Asteria's peak mount. The Titans approached like an advancing wall of doom, crushing landmarks and POI with the steps they make, to the point of quaking and breaking Islands on the way. Not even each Asteria's mountains or Zero Point were safe: the latter's petrified state shatters from crushing and give away now completely finite Zero Point energy.
"They're crushing the Islands!" Hoshimatsu pointed it out. "Petrified Zero Point shattering give us only finite energy!"
"Hello, guys!" Lex Pastore (ghost) greeted Lex Luthor of DCEU, accidentally scaring the latter.
The frightened billionaire-turned-prisoner then drops off the Bus, fall down to the high ground, eventually dying from the impact.
"Well, it's not necessarily the fall that'll kill a mortal." Liu Kang joked about the fall and eventual impact. "Do not laugh for the wrong reasons, and it's funnier and less offensive if you toon... so yeah."
"It's just what System and Kado and Evie have realized." Ellie Rose told her Bus, especially her friends Henry Stickmin and Charles. "The Rumbling has begun."
"Don't worry, guys... I'll take care of this." Post-timeskip Levi Ackerman then gave a cup of tea to Deadpool. "Hold my tea."
"Wait... isn't this just a multiversal version of some CGI-live-action-hybrid YouTube video already?" Deadpool recognized this.
Levi drops the cup, then for it to rift off and then fall down to an Artemis, breaking on the Sanctuary. "Come on."
Levi immediately leaped and then swung towards the Rumbling with his 3DM gear. Swinging across the Islands and approaching the (slow-moving) Titans at high speed, Levi manuevers and navigate towards the walking wall that has been infected by Anti-Life. Then a Titan fires a brief heat vision to the Surver Corps. ace, bursting his lower body and destroying his 3DM.
Levi falls down dead on the roof of an alternative Brutal Bastion.
"Oh, that was quick. And since the Titans are no more than a few times an Island's length from the Battle Buses..." Ace Ukiyo/Geats is disappointed.
Then that Bastion was, alongside Levi, crushed by a step not long after. Cue a facepalm from both Kyuju Kyu and Byaku Shin.
"Wait... we need to evacuate the entire Centipex!" Meden Traore realized. "Somebody rift it! Prime Town too!"
"Sure." Chya then opened the gateway and then focused to those place, to telekinetically scoop and take both places to go along the Buses. Both are successfully uprooted and floated out of Titans' way, also proving how powerful Chya is with the gateway.
"This power though could risk uncontrolled deconvergence, permanently splitting the Forgotten Four out of me. That, and the violent mind wipe and mind break by the Last Stop have to be prevented by my control." Chya proving her points while bringing Centipex and the town back. "Who else dealing with the Rumbling?"
"Kame..." Goku floated and then prepared for a Kamehameha, but an alternative post-timeskip Eren Yeager intervened.
"Fight already."/"戦え" Alt!Eren told everyone.
"Let's me go all out for this!" Goku then began his transformation, only to be slapped by Eren before said transformation could take off at all.
The rest of the alliance are shocked by the interruption.
"What!? He interrupted the transformation?" Travis complained. "Not again!"
"What's wrong with you, dumbass!?" Kyoman objected.
"Yeah, that's right!" The Paralympic mascots agreed.
"Fight already."/"戦え" Alt!Eren said it again.
"What should we do? The Titans is have a distance few times the dimension of an Island!" WILDS!Slone frustrated. "3DM will just be shot by heat vision! And none of our guns would cut it!"
"I have an idea." System suggested. "Kakashi Hatake has a special, forbidden technique that I saved."
"You mean the stickin' finger one?" The rest of the neo-Investigation-plus questioned.
"Exactly what I would ask, if was a friend of Kakashi's." Teras conceded.
"Nope, not that one." System denied. "This technique is the true pain, multiplied the square-cube law. 'Cause Titans are huge, after all, their gravity and pressure are extreme. Chya, channel the spell to the Islands!"
System quickly did a hundred hand signs, while Chya wirelessly grounds System's Battle Bus to the Islands. Then System plants her palm down the roof of the Bus she's above.
"Earth Release: LEGO Tech!"/"土遁・LEGOの術!"
Before the Titans, giant Lego pieces got terraformed, with sharp edges and all, spaced apart to balance density and danger. These Lego pieces, each roughly the size of an average building in an Island, ends up being stepped by the massive Wall Titans responsible for this Rumbling. The result is a wave of pain exaggerated by square-cube law repulsing the Titans, causing them to fall down, crushing their internals from both sudden gravity and mass impact.
"Yeah!!! You stopped them!" The alliance celebrated.
"It's too early, everyone!" Riane yelled.
"Bruh!"
The alliance stopped celebrating. And then, Nagato from a random timeline, overall better known as Pain, interrupted the scene, having witnessed the technique felling the Titans.
"Continuum Exploitation Authority! How dare you use the pain that's greater than mine!" Nagato floats up and objected the CXA. "Let me show you the greatest pain of them all!"
"Hey, were just trying to do our job!" Ms. Continuum talked back. "Mr. Pain! Get back to your world amd return to your timeline!"
"I agree with that blonde woman." The other Nagato/Pain - the one working for CXA - agreed. "Get out of here. we're busy dealing with something worse than you."
"We gotta shoot that random version, but how?" WILDS!Slone facepalmed. "We stowed our weapons inside the Buses!"
"Behold..." Pain about to perform that technique. "Almighty Push."/"神羅天征"
"He's going to do the Almighty Push!" Kogoro Tenzai figured it out. "We need to stop him!"
As the Pain floats up way above the Buses, the Claw cyborg has an idea...
"I think I have an idea." Zar activated his Serum W.
The Claw cyborg grabbed Alt!Eren and leaped off, assisted by Serum W.
"Interrupting time!" Zar threw Alt!Eren onto Pain.
"Almighty Push-"/"神羅天征-"
And... Alt!Eren flew off onto Pain of random timeline, causing both to crash down far away to a broken Island.
"Yes! This is how it feel!" Reboot!Ben Tennyson complimented.
"Hero pain!" The rest of Bens cheered.
"It worked! He interrupted it again!" Riane responded. "Now we just need to clean all this mess-"
"Look! Another version of the Last Stop!" Chya warned everyone.
Those looked at the windows that revealed. It was another gateway, similar to the one used at C Street in 1994.
"Not again!" Malal is frustrated. "How the hell did the Last Stop arrive without Anti-Life!?"
"Actually, it's already bonded to the Equation by this point." Chya facepalmed.
"What about the copies of the Zero Point!?" The Loopers complained.
"Many versions of the Zero Point in the same plane of existence? It's simple: Hypertime!" John Stewart - a Green Lantern - explained. "Zero Point is the same, no matter the period. Same state, at every timelines within a timestreams. There got to be multiple connected timestreams to allow more than one Zero Point to exist in the same plane of existence, and none of that would've been possible without Hypertime."
"So the destruction of the Zero Point doom its timestream. I see." The Loopers accepted the explanation. "Zero Point is not affected by time travel, so it's even more impressive for the vampire to pluck orbs out of its original timestreams!"
"Thanks for the compliment, but look at those two." Kado took focus on Pain and Alt!Eren. "Wait... the Storm is approaching too, syncing with... uh oh."
The Storm approaches the two corpses, at the same time the alternate gateway opens. From the latter, lightning strike made of glimmer - like the one that would've destroyed all memories as we know it - is somehow targeting both corpses. One of the corpses - that of Alt!Eren - happened to have a classic Nokia 3310 ringing, with someone calling.
Then both said lighting ans the Storm struck. At the same time.
"What the!?"
The lightning lasted for a while, but the Storm is then completely sucked into where the corpses were, alongside the terra-Lego pieces and the remains of the crushed versions of the Zero Point here (and its previously infinite energy).
"Oh no, this is bad! Bad as fuck!" Viola covered her eyes.
Quickly after, all the pieces and the energies was sucked empty. And from the corpses, a massive Reality Wave is cast, destructively leveling all the Islands below sans Centipex and Prime Town (held stasis by Chya earlier). The Battle Buses and co. are all hit by the Wave, though thankfully none of them of above are knocked off the roof, though the Buses are still knocked back.
"That was close! Thanks goodness none of us fell-" Travis however almost dropped down, but was saved by his grandson.
"Grandpa! It's dangerous!" Native Dancer/Scott Touchdown warned.
"Phew! That was even closer!" Travis is briefly relieved. "Now then... what the..."
A massive Titan, thrice the size of a Wall Titan but with human's body proportions and an exoskeleton-like arrays of giant OG-Nokia-3310-themed armors, and a Titan-ic (pun not intended) version of Nagato/Pain's face.
Everyone was shocked.
"The Nokia Titan..." Ms. Continuum knew it.
Cue a loud roar from the newly-amalgamated Titan.
"Mechas, go!" Ms. Continuum commanded.
The mechs immediately rushed towards the Nokia Titan, only for all of them to be frozen in place.
"Damn it!" Simon of Dai-Gurren is frustrated at his Gurren Lagann being frozen. "I can still supply with Spiral energy, but I cannot control this!"
"Not fair!" The Donbrothers realizing they cannot move.
"He's become a reality warper..." Chya figured it out. "Just like me. And miss System. And whoever truly godlike."
"Saitama, do what you do best. Punch!" Jumpson kicked Saitama down to the ruined Islands. "Good luck!"
Saitama, being extremely powerful and durable, survives the fall. He immediately assumed his serious side, and activated his killing intent.
And threw an overpowered punch, with far more than enough power to nigh-losslessly transfer insanely deadly kinetic energy, leading to massive whiplash of sound powerful enough to literally break grounds. This sent the Nokia Titan into a rift wall... and that wall broke due to the impact. Then the Titan rolled back, and leaped against the Buses.
"Go, Beast mode!" Commanded Jumpson.
Goku immediately assumed Ultra Instinct to make sure he has as much of a fighting chance as he could. Vegeta and Gohan did the same as well, with Ultra Ego and Beast mode respectively. The three then duked it out against the amalgamated, and cue the deathblows at a rate surpassing the speed of sound. A dozen of seconds later, the three was able to gather kick the Titan up to space, and then blitzed to punch him back themselves, crashing the Titan back to the ruined Islands.
"Oh." Angelica and the Bookhunter thinks it may be an unusually uninteresting sight.
And then Titan crashes, causing an impact large enough to send shockwaves that quaked the already-devastated cluster. Goku and Gohan prepped their Kamehameha, while Vegeta charged his Final Flash.
"Woah woah woah, enough, enough!" The real Nagato/Pain objected.
The three on the sky fired them, blasting the Titan concurrently. Cue a massive explosion that now only cover a few Islands, but also led to the rest collapsing. Cue the Battle Buses knocked upwards.
"Holy shit, this is dangerous!" The Canon Bringers are flabbergasted.
-*Instant Transmission* "Our only way to be sure." Vegeta reassured.
-*Instant Transmission* "Don't worry, we got the Dragon Ball-" Then Goku heard another thunder, coming from that other lightning from the same gateway.
The entire cluster started collapsing, though the mechs unfroze. The mechs immediately compensated with high ground...