Spoilers from included and/or represented works abound. Please read this fiction carefully.
"I am Midmyers Arc, the Chaos Taker!" He's Arc, the new Singularity.
"Half-homuculus much? Artificial legacy much?" Iroha argued. "We can still fight!"
"Opposition is meaningless. I was born to affirm the phenomena." Arc declared. "I also happens to be a mad scientist, and analysis of existence's variations."
"What if Cereza found you out?" Kyoman questioned.
"You... you two with cloned DNA in you, defected the empress!" Arc realized. "Not only that, you... just said..."
"You guessed that right." K/D laughed. "The Zerobreaker, she abused us and treated us as killing weapons."
"Even Arch-Eve... How dare you take her directly into equation!" Arc is disappointed. "She doesn't exist anymore! She died and died and died fighting my father!"
"Here." System face Arc the note from the box that had the guns.
Arc read the note, and is irritated even further.
"If that be it, I'm gonna possess her ass!" Arc then blasted himself, knocking everyone away.
"No! He's too strong, just like his father!" Tee then nearly passed out.
"That power... At this point, he's even stronger than when he used several powers to empower himself, while inside the TV world...!" System took note. "What has he become..."
"I can read your mind, you twigs." Arc told them all. "Any attempt to defy the phenomena affirmation all thought to be undisputable, shall be annihilated and overkilled on sight."
"To make sure Arch-Eve doesn't defy my father's legacy, give me the guns." Arc threatened.
"He noticed the guns we're holding!" Schezo realized.
"Hand me the guns. Now!" Arc screamed.
"Psycho-Singularity... You've left us with no choice." System then snatched all the guns. "Here, take it."
The Bayonetta guns went to Arc.
"Why... we could've been better with the guns on us..." Amitie is disappointed.
Raffina, Sig and Klug facepalmed in response.
"He'd kill us all if we don't hand him the guns!" System bluntly replied. "And if we don't survive even another day, the CXA is gonna lose the fighting chance against the Anti-Life eventually."
"Good." Arc takes the guns. "Because you listened, I'll spare you all... for now. Remember this: there is only one, singular, immutable truth."
"Your struggle will prove to be pointless." Arc then flew away. "When I'm back to you, that would mean... Arch-Eve is mine!"
"He's Singularity but psychotic." Iroha sighed. "Full-on singularity plus psychotic madman equals madness incarnate."
"He's even worse than the original ever has been, right from get-go...!" Viola is frustrated. "And worse still: Mummy is in danger! Again! Even more! Argh!"
"Our objective now is to find Ringo and Kamisaman." Tee got up.
"Ok... who's gonna be found first?" Lemres asked. "I want sugary treats so bad, by the way."
"Awww, you're short of candy." K/D then took out a swirly lollipop. "Here."
Lemres immediately took it and ate.
"About Kamisaman... The mysterious girl who appears to have created White Room and invented the Kamisaman System which consists of the Omnisphere, the Dynamisphere app and Sabbath battles, etc." Iroha wondered. "Do it ring a bell to any one of you?"
"Kamisaman created the Dynamisphere, even installed it on all new phones... wait..." System noticed. "If she's behind the app and Omnis, maybe she could have some special thing about it! Maybe... she too could become a magical girl, if she so choose! She's biologically sister of Omnis!"
Cross-trivia: Kamisaman's Dynamisphere technology transform the heroines' smartphones into "Magical Instruments" based on their personal traits.
"Then that means... we can't take on Ringo right now?" Arle is disappointed.
"We only know Ringo is in the Trinity of Realities, but not the exact alternative verse." System replied. "Too fucking vague to assume where she is right now."
"Very well... Let's go find Omnis! And contact to Kamisaman!" Iroha has made her decision. "Let's go!"
A while later...
"Hello there, Iroha Asobe."/"おかえり、遊部 いろは (あそべ いろは)" Kamisaman greeted Iroha. "Wait..."
"Who are you!?" Tobio, known in action as Omnis, is surprised. "You're not even from any timelines I have experienced ever before recently!"
"Now now, we're guests from distant worlds!" Arle replied. "We're investigating the New York City, trying to find a girl named Ringo Andou."
"You're Isana Hakari, isn't that right?" Amitie replied. "I'm Amitie! I hope we work together as friends and comrades!"
Kamisaman's real name is Isana Hakari (量 沙奈 (はかり いさな)).
"NGGGRRRHHH! IT'S ME, KAMISAMAN!" Kamisaman gets angry.
"You've got Dynamisphere on all the new phones, huh?" Iroha asked Kamisaman.
"What? You're going to force me to awaken Kamisaman as a magical girl!?" Tobio is shocked.
"Sabbath Arena are actually a system to decide which executor 'has the strongest possibility'. The Executor who wins the Sabbath Battle rankings will be become the next Kamisaman." System told Kamisaman. "Unlike you, the present Kamisaman, the new one will have a new ability toretconall the universes that have been impacted by the demons."
"And since you're a female Kamisaman... maybe you could try accept the call and become a magical girl." System suggested. "Even if Sabbath Battles are done, you still has works to do. Besides, your brother knows how to bring fourth new possibilities, just like me, and of course, do the retcon once it's all over."
"A magical girl transforms by launching Dynamisphere, and then kiss the phone while the app is active." Tobio recounted. "That's how awakening a magical girl be like for me, alright?"
"This is a special case though. Female Kamisaman, let alone being your sister, means that she could potentially become a magical girl." System told Tobio. "The only other ones eligible to this are those who would have any desire to romance and play out with you in any timelines you can possibly imagine as Omnis yourself."
"Iroha wanted to be a magical girl... I guess you should too. You're a girl, and has the power." Tobio/Omnis suggested. "And they said we must cooperate with them. As an amnesiac Executor trying to protect the magical girls and fight demons... You have my word."
"Rift Beacon, just in case." Ma installs a portable Rift Beacon. "Anyways, you better become a magical girl, because that's for the best."
"The flux is gonna destroy us if we don't take action!" Kyoman scolded Kamisaman. "Use your phone, it has the app!"
Kamisaman reluctantly took out her phone, which indeed has Dynamisphere installed in it. She opens the app. However...
"Isana... found you." It's a polygon clone of Aloy, made of the All-Stars energy.
System noticed it from behind, and... "Watch out!"
The polygon shoots an arrow towards Kamisaman, but System catches it.
"All-Stars energy around..." System noticed. "What's this!? Who told the Polygon Man to send this clone!"
The polygon then jumped in, but is crushed by a Tetris clear.
"Crap. Interrupting people's business for all the wrong reasons..." Tee is disappointed. "Now that the app has opened, kiss your phone."
"You, hurry! Some demons are infiltrating an important location!" Tobio shouted. "Demons eat a human's existence, and it's our job and mission to save them!"
"Here goes nothing!" Kamisaman kisses the phone on its screen.
It seemed like it doesn't work... until this voice said: "Do you believe in limitless possibility?"
"Finally, it's ready." Tobio responded. "Do it again, but for real!"
"Very well then... I believe in limitless possibility!" Kamisaman then kissed the phone again.
"Use approval confirmed." The voice in the phone commanded. "Commencing with collation of Kamisaman system data."
"Alright! I think this will work!" Tobio exclaimed.
"1... 2... 3... Collation of all data confirmed." The phone computed. "Kamisaman system... stand by... Kiss me please!"
"Kiss it, for real, for real!" Arle exclaimed.
Kamisaman kisses the phone yet again, this time to activate the transformation. Her body immediately glew up... literally.
Then, before long, she's dressed in a special outfit. It's the magical girl type of outfit Tobio shown for each of his magical girls in their main appearances as well as Ultimate Magica, but colored in palette of every colors Omnis's magical girls represented, from pink to blue to yellow to purple and so on, and integrated into the white long sweater Kamisaman (and for that matter, Isana) wears, turned frilly. The rest of the clothes turned to the same palette, and she's now wearing white shoes styled after magical girls, also Omnis's. Her eyes became shiny with the same magical colored irises matching the clothes, and her hair is still the same long style and bluish light gray (much like normally) but with highlights of the same magical colors from the underside, foolish hair and select strands. Ribbons is in her dress, and her (small) phone is attached as a hair accessory, completing the look.
"Me... a magical girl?" Kamisaman is surprised. "I feel... so powerful. I feel... infinite possibilities is on my grasp... I feel... like a goddess, complementing you... Tobio."
"Kami-sana!"/"カミさな!" Lemres squeeed. "You did it!"/"やったっできたね!"
The entire group briefly celebrated, as Kamisaman feels the powers of what a magical girl for Omnis should be.
"Could this be? That means... could there be a possibility of me becoming Tobio's wife..." Kamisaman is surprised. "And I'm... a special one too? Am I..."
"Kamisaman. You can get out of this white room." Tobio pats Kamisaman's head.
"Our next step is to survive, slay the demons that erase people's existence, and find Ringo!" Amitie exclaimed. "Leave the Rift Beacon to control this place! Let's go!"
Everyone leaves the white room, leaving only the portable Rift Beacon, which is made with the Seven's technologies, inside.
A while later... turns out none of the magical girls Omnis lost track of this far are dead. They're alive, but struggling in the fights. It's the Anti-Life-enhanced Phantom Ruby that caused Iroha to think that they're all killed. However...
"What did you do to all the worlds?" Kaori Tomonaga (朝永 花織 (ともなが かおり)) questioned.
Seira Sodeshiro (袖城 セイラ (そでしろ せいら)), Cocoa Yuwase 百波瀬 ここあ ((ゆわせ ここあ)), Akisa Higashiyama (東山 陽彩 (ひがしやま あきさ)), Ao Ohtori (大鳥 蒼 (おおとり あお)), Aka Ohtori (大鳥 丹 (おおとり あか)), Eliza Yukifune (雪船 エリザ (ゆきふね えりざ)), Lilly Yarimizu (槍水 りり (やりみず りり)), Hanabi Tamaki (環 はなび (たまき はなび)), Marianne Okada (丘田 マリアンヌ (おかだ まりあんぬ)) and Iko Oikawa (及川 依子 (おいかわ いこ)), are all accompanying Kaori, facing against Argimed, who's possessing the power of the Phantom Ruby.
"Well, we're raiding your worlds with this ultimate power!" Argimed boasted. "It feels good to return with this great power! Reality will dictate your fate, because..."
"It prevents us all from seeing the real worlds after all." Eliza replied. "It effectively change our prespective of reality. Simply put, it's a lethal series of illusions."
"You guessed it as correctly as a non-saavy strangers could possibly guess." Argimed laughed, and it's hammy and loud. "And now, with the Anti-Life Equation and the Zero Point energy infused with darkness and void all syncing and boosting the Phantom Ruby, the reality itself will submit!"
Argimed then used the aforementioned powers to make fakes of Darkseid, Infinite, the Cube Queen, mutant Nemesis, Parallax, Al Azif Ex-Mortis, Kang the Conqueror, Infinity Ultron, Susano'o, the Storm King, Batman Who Laughs, a Tyrannosaurus Rex, Another Decade, Fused Zamasu, Aizen Sousuke and the Evil Omni-King Archon.
"Previously, it only has so much power it can use at once before weaking by overextertion." Argimed continued. "But now, it became limitless! Phantom Ruby is now unstoppable! You must thank Anti-Life for it, no-"
"Shut up!" The magical girls shouted.
Then they tackled Argimed and the fakes, only for the latters to instantly dodge.
"What the?" Seira noticed. "They dodged us all...!"
The fakes attacks the magical girls, eventually leaving them even more bloodily wounded than just before. The girls did manage to fend off some hits and dodge things in the process though.
"Damn it! We may be going to die!" Kaori spits out blood.
"No... none of these... are making sense...!" Akisa found out the hard way.
Ultimately, the girls are on verge of death. The civillians from other worlds saw it all, and they're horrified at the sight. And even worse: the said beatdown they just saw takes place in a broken flux, stuck between Earth-199999/MCU-616 and the Earth-10 (also known as Earth-X) from the multiverse of 52.
"There's no reason to resist. Because the Kamisaman system is over!" Argimed declared.
The dread commanded the fakes to split up, leaving the magical girls to die, and he used the Phantom Ruby powers to kill the civillians nearby. Argimed thinks that the girls are no longer worth finishing off, so he spotted a sole surviving Umbra child wearing glasses.
"I can taste your terror, Cereza." Argimed noticed Cereza. "All that anxiety and doubt... It's delicious."
Argimed shoots to only barely miss the child. "Give in to your fear. Flee, screaming, and I'll let you live." *evil laughs*
Cereza simply ran away, holding the toy kitty named Cheshire, and crying.
"Your insistence is forever futile... so does the free will!" Argimed raises his fist. "Anti-Life Is! Anti-Life Is! Anti-Life Is! Anti-Life Is! Anti-Life Is! Anti-Life Is! Anti-Life Is! Anti-Life Is! Anti-Life Is! Anti-Life Is!"