Spoilers from included and/or represented works abound. Please read this fiction carefully.
"You'll be executed shirt after the sacrifice." A(n Sigma-Virus-infected) Stormtrooper told System No. XX.
"It's you, Kansatsubi Kousako." Someone on the right of System No. XX.
"What? A Monado boy?" System No. XX is confused.
"I'm Alvis, the administrative computer of a phase transition experiment facility." The Monado boy introduced himself. "I'm the Monado."
"Does it matter anymore?" System No. XX asked. "We might die anyways. Both of us in particular will get destroyed."
"There's still hope and progress." Alvis replied. "I can sense it in the shadows, that someone will emerge from there and save the day."
"Oh, Mr. Monado." Rachel, on the left of System No. XX, noticed Alvis.
"Someone will save the day." Alvis reassured. "I'm sure of it."
"Here goes Rosalina..." System No. XX. "Is there's any hope left for us?"
Some Stormtroopers bright Rosalina to the center stage for a ritual similar to Aionios' Homecoming. Rosalina seemed distant towards the alliance, as if she has agreed to betray then all and go accept Genjitsu-no-Omnia.
The Stormtroopers on the stage then removed their helmet, revealing them to be descendants of whoever Genjitsu-no-Omnia abducted in her early hops and invasions. They then all took the flutes for this 'Homecoming ceremony'.
Finally, the Stormtroopers on stage played a flute melody much like that from Aionios, with Genjitsu-no-Omnia behind Rosalina in the center, and the servants on the front and side, looking at Rosalina and saluting. Rosalina gets sent off and seemingly dies as bright white lights flying off and upwards and away, similar to in the latest incarnation of a Homecoming ceremony.
All of this, while the prisoners are forced to watch it all, as Rosalina is sacrificed for Cursa, seemingly dying as a person. System No. XX and Rachel, in particular, both shed tears over the sacrifice. The 'ceremony' ends with Rosalina disappeared and Genjitsu-no-Omnia smiling.
"All hail!" Genjitsu-no-Omnia's servants saluted.
"Rosalina!!!" System No. XX, Rachel and Marie/Izanami shouted agonizingly.
The Stormtroopers holding the prisoners then prepared to execute them all.
"Rosalina..." System No. XX mumbled... and starts crying.
"You existed very well." A Stormtrooper told the prisoners. "The execution commences."
The Stormtroopers took their lightsabers and is about to decapitate the prisoners simultaneously.
"Last words?" The Stormtroopers asked.
"She's dead..." Rachel concluded. "Rosalina as a person... us dead."
"What did we do wrong?" Marie/Izanami questioned everything.
Then the Stormtroopers proceeded to slash off the heads.
time stops*
Labrys and Ren Fuji emerged from the shadows behind, having sneakers the 'ceremony'.
"You have done an extreme damage to the hopes from the cosmic Sparks." Ren Fuji became Tenma Yato... again. "Yatsukahagi, rise!"
Labrys started snapping, and quickly drank the drug dose that David used to take.
"Urgh!!!" Labrys quickly malfunctioned.
Time paused, and all the members of Yatsukahagi has been summoned on top of the shadows. The Stormtroopers stopped before the light blade could touch for execution.
"Huh?" System No. XX then looked behind.
Labrys' body jerked, and she vomited the some... liquids. Then she seemingly shut off, limping around.
"What the hell!?" The Stormtroopers panicked, dropping the execution for. "We have spies lurking behind!"
"I knew this is similar to when I was to be executed, and M's in Mio's body getting sent off in her Homecoming!" Noah realized something, having emerged from the shadows.
The alliance emerged from the shadows.
"We've been hearing and spying from this fake ceremony!" Ushio revealed.
"I knew Rosalina would be sacrificed for nefarious purpose!" Jumpson confirmed.
"It's you all again!" David recognized the threats.
"Genjitsu-no-Omnia... My wrath is coming to you!" Hajun warned Genjitsu-no-Omnia.
"I remember you. That god I shrugged off in Reality Zero!" Genjitsu-no-Omnia recognized Hajun.
"For Rosalina, and for the omniverse!" Rabbid Mario shouted.
"Rosalina did nothing wrong!" Rabbid Rosalina argued.
"Hmph." Genjitsu-no-Omnia then teleported with Sandevistan.
"It's you again, you lowlifes!" Prometheus noticed. "And then some!"
"Good." Rachel and Marie/Izanami stood up.
"Then I'll come." System No. XX stood up, and summoned her outfit. "It's back to normal, and we have seen it coming."
This brought a transparent gradient (blue, yellow, purple, red) dress on top of her shirt and skirt, and a physically-simple bomber sukajan with the same engravings and details, matching that of the shirt, skirt and of her machine form. She's wearing that off-shoulders, exposing the (shirt's) hood as well. Then a similarly mechanical boot completed the uniform. Her hair has the bangs back, but remains the same length.
"Finally!" Alvis summoned his Monado: the true Monado.
"Look at what we got." Rigna noticed. "The execution is forcefully cancelled by the shadows lurking around. Creative stealth you've got."
"Also, you've got your powers back!?" Rigna turned attention to System No. XX. "Are you even human or machine anymore!?"
"And you, Angelicarmen..." Rigna then turned attention to Angela and Carmen. "You betrayed us and found the Sephirot!?"
The Sephirot then laughed at Rigna, mocking him in the process. But among the laugh, Labrys also as well.
stands up* "All right, who's coming at it again!?" Labrys then opened her eyes, revealing the yellow ones. Turns out Shadow Labrys took control.
"Shadow Labrys!?" The Shadow Operatives and Marie/Izanami are shocked.
"I beat up that guy and those minions, you beat up that robot!" Shadow Labrys suggested.
"There's Umbras cube in Prometheus, so if we take it, he'll be killed!" Jumpson told the alliance.
Much of the alliance then fended off the Stormtroopers, while Shadow Labrys caught and tried to beat up Rigna who's wielding the x-blade.
"Persona!" The Persona users summoned their Personas. Marie/Izanami in particular turned for her Persona: Kaguya-Hime.
"Asterius, come!" Shadow Labrys summoned her Persona, Asterius.
Rigna ultimately ended up having to contend with the 'Raging Bull of Destruction'. Meanwhile, David, Jumpson and Velvet Meteor took Prometheus.
"Combo with Jumpson has two forms, depending on which mode your MeteorGun is currently set in." Jay-P notified Velvet Meteor. "In Gun Mode, you and him fires a fused Kamehameha with Umbras energies. In Flash Mode, you both stun your opponent and heal yourselves."
"Combo with David let you and him move around with Sandevistan and shoot your nearby opponents." Jay-P continued.
David shot Prometheus right arm off, but it quickly attached back telekinetically. Jumpson then slashed behind.
"Use the Power Combo with Jumpson, and you'll shoot him, he absorbs your projectiles, then he beat up off the opponents nearest to him." Jay-P concluded. "Using the Power Combo with David, and you'll use Flash Mode to stun or distract enemies, then David will use Sandevistan and kill them all off."
"Die, kid!" Prometheus then proceeded to fire laser towards Velvet Meteor.
Velvet Meteor Combo with David, dodging the laser, moved around through using Sandevistan, and both continuously shooted the Daikaiser.
"Damn! You shall not!" Prometheus gets shot.
"Go, Jumpson!" Velvet Meteor then Combo with Jumpson, firing MeteorGun and Umbras with Kamehameha towards Prometheus, knocking the Daikaiser down.
Gabimaru and the Princess approached Prometheus, and Velvet Meteor is fully powered now. They proceeded to do the Power Combo.
"Take this!" Gabimaru fired up on circle to burst... and the Princess swung EX with fire to slash Prometheus off. The combined Power Combo properly damaged the armor, creating a hole exposing the lower chest.
"Now, Jumpson!" Velvet Meteor then shot Jumpson, initiating the Power Combo with the last of the required charge.
"Jump the Umbras!" Jumpson absorbed the shot and charged up.
Jumpson then instantly approached Prometheus, and then used his Umbras force hand to stab the Daikaiser.
"Found the cube!" Jumpson then quickly grabbed the Umbras Cube from Prometheus.
"Nooooo!!!!!!!!!!" Prometheus screamed in massive hurt.
"It's over, Prometheus." David pointing his cyberarm's cannon on Prometheus' head.
Prometheus' body glitched again, this time much more violently. David simply had shot him, killing the Daikaiser once and for all. The armors disintegrated, the Black Lanterns' energies and the Sigma Virus is lost, and the Infinity Stones floated ahead and out to David's grasp.
"Finally, he's dead." David retrieved the Stones.
"He deserved it for messing with the Jump worlds the wrong way." Jumpson commented.
Sandevistan and dashed to the spot* "Prometheus!!!" Rigna is horrified at Prometheus' death.
"Oh, so the Keyman is dead?" Shadow Labrys noticed.
"You!" Rigna approached Jumpson, and tried to take the Umbras Cube away. Jumpson simply distanced the Cube away from Rigna, and summoned a copy of Star Platinum.
"You'll already be dead." Jumpson dodged.
The Star Platinum clone then proceeded to finish Rigna like Kenshiro would typically do to an opponent, but Rigna dodged it all with Sandevistan...
Only for Shadow Labrys to grab him.
"Labyrinthos Gate!" Shadow Labrys finishes Rigna off with that finisher. (Yeah.)
By that point, most of the Stormtroopers there has been killed, while the surviving ones were defeated and ran away.
"What a drag..." Yosuke is frustrated. "Come on, you pain in the ass!"
"Genjitsu-no-Omnia escaped." Yomi noted.
Rigna is now show lying around, severely injured. Sora took the x-blade.
"This is what you get for destroying Kingdom Hearts." Sora told Rigna.
"He's right for once, Rigna the Bloodrunner!" Shadow Labrys mocked Rigna.
"Asterius, good job!" Shadow Labrys then took out of summon. "I'm out."
Labrys then fell down.
"Labrys!" The Investigation Team approached Labrys.
"Don't except any true mercy from us." Fusion then ran away.
"Uh... What's wrong?" Labrys woke up. She's fuzzy.
"Your Shadow just beat Rigna up." Mickey Mouse revealed. "Finally, some classic karma!"
"Oh, the fuck..." Rigna limped around.
Magsarion then crushed Rigna's head with his sword.
"Done. If you want to purify this place, do it!" Magsarion exclaimed.
"Without direct influence from Genjitsu-no-Omnia, we should be able to purify and retake my Library." Angela replied.
"The Remorseless, I like you being... remorseless, and I'd like to lust-"
"If you glorify your sexual interest in front of the public, the childs and the sensitive ones would be disgusted." Ann Takamaki (Panther) warned Mitra.
"Whatever." Mitra facepalmed.
"Rigna's dead." David realized. "Prometheus is killed, and Genjitsu-no-Omnia and Fusion left. We should be able to purify it all."
On that relative noon (Day 16), the Library is purified, and Angela took control of it again, with Carmen once again acting as its will. This time, it's treated properly, and it's the Seed of Light, so it's now possible for Library to fold down for Carmen to carry over. The Library of Ruina now also acted as an extra HQ for both Shinra and Ouma, with the variable gateways to other worlds being the things carried over from the Library of the Rifts.
"A portable HQ..." Ayin commented. "Nice."
"Be glad Angela and Carmen is there to help save the reality." Roland told Ayin.
"Angela hates me bow, though..." Ayin replied. "The experiment became a permanent failure, after all..."
"I could've had revenge on her, or vice versa, but both of us has since learned to forgive and move on from such vengeance." Roland explained. "That's part of why I ended up getting along with Angelica."
"The Sephira has place again." Ayin commented again.
Meanwhile, in Taa II, Galactus's Mobius-strip-shaped worldship in its actual size (overwhelmingly larger than the Solar system), the mechas has already gathered.
"Cursa is coming for us." Masaki told everyone.
"The Mega Megazord, huh?" A mysterious woman who's like a machine. "And there's Mega Gravezord as well-"
The mysterious woman then went into the cockpit of the alien Megazord.
"What? Who're you!?" All the Power Rangers doesn't know who she is.
"Cross-Dimensional Observation System No. XX, human name Kansatsubi Kousako." Zenkaiser introduced the woman. "Shinra to some of us about this crossover machine."
"Wait, what?" Green Ranger is confused.
"I have so much to read out of your mechs!" System No. XX laughed.
"Hey dude..." Various mecha pilots called.
"Hundreds of robots to counteract with Cursa, well?" System No. XX guessed the tactics.
"You know Cursa!?" Alternative Jason Scott, the Red Ranger, is shocked.
"That Megabug fused with the cosmic energy?" System No. XX replied. "It's back, and possessed Rosalina again. This time, it's not just possession anymore... It's a proper fusion."
"By the way, as you all know, Cursa won't go alone." System No. XX warned everyone. "There'll be various other threats going against you all."
"Guess what?" The Gokaigers replied. "More monsters to beat!"
"I can survive in space, but because space is basically vacuum, you won't be able to directly hear me at all." System No. XX then got out.
Ende the Devourer, corrupted Nevanlinna piloting Arcadia, Hypsistos Z, XN-L (pronounced 'Zan-El'), Adamatron, Neo Granzon, Judecca, Angilon, Larva in final form, corrupted Einst, Al-1, Son Ganlong, Perfectio, Devil Gundam, Nashim Gan Eden alongside Kanaf, Keren and Zanav, Chojin Zest, Hellruga Izberga, Kali Yuga, Gaiou, Gauron, Emeraude, Gadlight, Nyarlathotep, Azathoth, Yog-Sothoth, an massive army of Kyō-Mugann and a shit-ton of loads of load of runes, all appeared through the Sideways Rift in front of the mechas.
"The threats is already there, and Cursa is coming soon." Ryo Nagare warned everyone. "Get ready!"
Not long afterwards, a giant Cursa emerged from the Sideways Rift and stood tall alongside the threats.
"I am Cursa, the Hope Crusher!" Cursa introduced... 'herself'!? With Rosalina's voice reverberated!?
"I don't really remember Cursa talking by... um... itself before." Barrel is confused.
"If we let our guard down, we'll be exterminated." Fei warned everyone.
"I am but the ultimate end of all hopes of whichever be will be." Cursa exclaimed. "I shall put you in despair and extinguish all the remaining hope that's left!"
"Who the fuck are you!?" Rand asked angrily. "And why are those threats we once fought in our adventures got back!?"
"Simple: I, Cursa, possesses beings like these and imbue them with the powers of destroy all hopes."
"Friendship, unity, that's how we will rock!" Pilots shouted.