MIR-203 Selene Sheryl 

MIR-203 "Selene Sheryl," a Mainframe-made autonomous exploration program.

As the Metaverse continued to thrive and grow, no matter how mighty the Mainframe's power and authority, it was difficult to grasp the full picture. That was why many exploration programs like Sheryl were created to take on the duty of accurately surveying the world.

Sheryl was a detection type exploration program 4500 cycles young, who was tremendously accomplished with her natural composure and superior detection ability. There were two other programs from the same line—in other words, her older sisters. MIR-201 "Hecate Beatrix," an attack type with a fittingly bright and hearty personality, was the dependable eldest sister who led the timid Sheryl and her other sister MIR-202 "Artemis Lena" along. Her other sister, Lena, was an all-rounder program—a well-balanced program who could respond to any kind of situation. She was earnest and upstanding, and Sheryl loved and respected her deeply.

As exploration programs created by the Mainframe, there were high hopes for the three sisters, but typically they acted like any close sisters their age would. They visited highly praised cafés together and went out shopping for clothes.

One day, while Bea was watching the anime "BeastDream," Sheryl ran in with a game.

"Bea! Race me in this game!"

"What's that? ...Oh yeah, this thing's popular right now, huh?"

"Yes, apparently the sense of speed is great... Anyway, race me! I need to make up for getting humiliated at that fighting game the other day!"

"Hehehe. Fine! But I won't go easy on you, 'kay? ...I might thrash ya again, Sheryl! ♪"

"Do your worst!"

Watching the sisters enjoying themselves as the racing game got heated, Lena smiled and sipped her tea. "When your match is over, want to take a break? I just made cookies."

The three sisters were always together. Just seeing each other's smiles was enough to fill their hearts. These peaceful days would go on forever...or so they believed.

Sheryl and her sisters received orders to investigate the "outer edge," the farthest end of the ever-expanding Metaverse. It was an uncharted domain that had yet to be properly surveyed, with all kinds of theories about it floating around. It was said that malicious "Nemesis" avatars often appeared from within.

"Why've we gotta search this outer edge all of a sudden?" Bea grumbled. "What's up with the Mainframe higher-ups?"

"It seems like this mission came directly from Lord Typhon," Sheryl answered.

"It did?"

Typhon, the king of the Metaverse—he sat at the center of the Mainframe, wielding his mighty power.

"But apparently they've already deployed five other exploration parties like us to the outer edge... I heard none of them made it back safely. We have to brace ourselves for this mission."

The other sisters were breathless at Lena's words.

Then, to dispel that fear, Bea said, "It's gonna be fiiine! Any kinda trouble you throw at the three of us is gonna be child's play! Malicious avatars, big new monsters, bring it on!"

Lena and Sheryl slumped their shoulders.

"...We'll have a serious problem if they all just show up like that!"

"Hahaha! I bet!"

"Hehehe... Come on, let's go... To the unknown outer edge. And then all three of us are returning together to the Mainframe, no matter what."

"Yeah!"

"Yes!"

And so the three sisters headed to the farthest end, where they achieved a magnificent victory against a vicious Nemesis program called Pandora Nemesis. They succeeded in bringing home data on the outer edge to the Mainframe.

However... On their journey, the three sisters learned the hidden secret of their birth. They met mysterious programs there called Old Blue and Wiseman. These two told the sisters that they were hybrid life-forms fused from humans and programs. Installed with the human system of "evolution," they held limitless possibilities, but the strain on their data was extraordinary, and because of their characteristic of constantly changing, they could not go back... In other words, their lifespans were limited.

In addition, the sisters had always believed that the Mainframe's orders were absolutely correct. The Mainframe's mission was to be protectors of humankind. The sisters took pride in carrying out such a mission... But Typhon himself, the Mainframe's king, had disgraced their very reason for being...

From the secret of their birth, to the loss of their pride, and the sudden news of their destined end...the three sisters hearts' were shaken.

After reporting what they found on their exploration to the Mainframe, Sheryl and her sisters began to investigate the secret of their birth.

"Is what Wiseman and Old Blue told us true?"

The sisters had found out that they were born from experiments conducted by Typhon himself. But they knew nothing else, so they took action to learn about their own upbringings and the real reason they were created.

They went to the Mainframe's Foundation, where they were born, to ask the development programs who seemed to be involved. However, they were apparently born under martial law imposed by the Origins, and the programs absolutely would not speak of it.

"Where can we find the truth of our birth? ...Would we be happier forgetting everything instead of holding all these doubts?"

As those discouraging thoughts were passing through their heads, an unexpected person told them the truth. It was a program responsible for regularly adjusting them. He once worked at the Foundation and took part in their development.

He deemed Wiseman and Old Blue's warning to be fully correct. So Typhon's inhumane experiments were, too...

"No way..."

Deeply shocked, the sisters thought it over, but the adjustment program wouldn't tell them any more details.

"...I'll leave the rest 'til next we meet."

Those words would become his last. The next time the sisters went to visit the adjustment program, they learned that he had been disposed of.

"Why!? He wasn't doing anything wrong!"

The three sisters sought an audience with Typhon once again. They asked him about things like the circumstances of their birth, the disposal of the adjustment program, and the Mainframe's mission, but his response did not satisfy them.

Instead, Typhon ordered them to stay on standby until their next mission.

Typhon ordered the sisters to stay on standby in their room until their next mission. They were temporarily stripped of their abilities and forbidden to access any place outside the Mainframe's administrative domain. It was effectively imprisonment.

"What are we supposed to do from now on?" Sheryl asked, unable to hide her fear.

"It's okay, it's going to be okay..."

"Lena..."

In contrast to their grave faces, Bea's attitude was carefree.

"Yup, gonna be fine, just like Lena said! We're actually kinda lucky if you think about it! We've been doing nothing but work, work, work lately—just think of it like a longer vacation!"

"Bea..."

"That's right, it's just like Bea said," Lena added. "Let's restore our spirits now to think about what we'll do from now on."

"...You're right."

They all took a different attitude to their imprisonment, but their feelings were the same.

We're going to keep on surviving as sisters. For this world... For our future!

And then, someone muttered from nowhere, "...Let's escape from the Mainframe!"

One day, when the three sisters' suspension was lifted, they were contacted about a new mission from Typhon.

Now that the Mainframe had called upon them, they checked that their own powers had been restored.

"...Yep, seems like it's all a-okay. We're in tip-top shape."

"But we shouldn't let our guards down."

"Yeah, guess the Mainframe's not totally safe for us anymore."

"Yes... Let's act as if we're following orders from above, then make a break for it!"

With their plan set, the sisters entered the throne room where Typhon awaited them. However, Typhon was not there—his close colleague and fellow Origin, Battle Master Goetia, waited there in his stead.

"...So you've come, MIR series. I have orders for you from Lord Typhon. ...Come closer."

They felt something was wrong, but the sisters approached Goetia.

"Your orders from Lord Typhon...are to die!"

"...Watch out, Lena!" Sheryl called.

"Huh!?"

At the same time, Goetia shot his fist toward Lena at incredible speed. With her superior detection abilities, Sheryl shouted instantly, enabling her to dodge the attack. That fist became a sharp assassin's blade, slicing through the air and cutting several strands of Lena's silver hair.

"You should be glad... We Origins will achieve a new level of program thanks to you, the hard-earned successes of thousands of experiments!"

"Are you just going to keep doing your cruel experiments and create more beings like us!? And you claim to be the Mainframe!?"

"Silence! Those who defy Lord Typhon must die!"

Goetia called on his hidden underlings to attack the three sisters. Even though they anticipated the attack, their opponent possessed the overwhelming power of an Origin. They could do nothing but defend in the face of Goetia's might.

"Ahhh!?"

Goetia's fist turned a sinister shade and grabbed at Sheryl! Lena immediately stood in front of her sister.

"Look out, Sheryl!"

"Lena!?"

Lena took Goetia's attack in Sheryl's place. Goetia's fist, glowing a deep purple, hit Lena many times, rendering her unconscious in an instant.

"Lena!? Shit! What the hell do you think you're doing to my precious sister! You jackass!"

"Lena... You protected me again... He won't get away with it!"

Perhaps because of their emotions at seeing Lena wounded, Bea and Sheryl's power rose all at once! For a brief moment, their power was enough to surpass Goetia.

"What!?"

All Goetia could do was defend against the awakened Bea and Sheryl's attacks. Then, when they found their opening, Sheryl and Bea prioritized escaping from the Mainframe instead of continuing the battle.

"That...was...the evolution of programs."

Left behind, Goetia felt the threat of the three sisters' potential for the first time.

The three sisters escaped from Goetia and fled the Mainframe, but they had nowhere to go.

"Haah...haah..." Bea panted.

"Lena... Please, stay strong! Open your eyes! ...I'm sorry, it's all my fault."

As Sheryl cried, clinging to Lena's unconscious body, Bea said, "Sheryl, right now we gotta focus on taking her somewhere safe, where the Mainframe can't detect us."

"But...where are we supposed to find a place like that?"

As exploration programs, they knew better than anyone how far the Mainframe's search network spread.

After thinking for a while, Bea said quietly, "Let's go to the outer edge. Not even the Mainframe can find us there."

"What...? You want to go back!? How are we supposed to treat Lena in someplace so remote?"

"Still! Better than the Mainframe catching us! If those guys catch us, they'd delete us for sure!"

"Bea... Understood! Let's go to the outer edge!"

"Yeah... Lena, hang on a little longer. We're gonna save you, I promise."

With that, Sheryl and Bea evaded their Mainframe pursuers all while protecting the injured Lena before managing to make it to the outer edge.

When they arrived, they wanted to feel relieved...but Lena's worsening condition worried them. As human-program fusions, the sisters were supposed to be constantly restored and strengthened in exchange for their lifespans. Wounds from physical damage should have restored themselves right away. However, Lena was only getting worse instead of recovering. Seeing the data gradually crumbling away from her wounds, Sheryl and Bea hung their heads.

"Lena... Please, open your eyes," Sheryl begged.

"—That young lady is afflicted by a poison. Left as is, she will die before she ever wakes again."

"Who's there!?"

Sheryl and Bea stood on guard against the lanky man who suddenly appeared. He began surveying Lena's body, paying no mind to their alarm.

"Oh...? This is Goetia's poison. It will be troublesome to analyze."

"Hey...! Who the hell are you!?"

"My name is Old Blue."

"Old Blue... That's who Lena said she met here at the outer edge," Sheryl said.

They had only heard his name from Lena, so they were wary of his suspicious behavior. However, they had no allies here at the farthest end. He was a bit questionable, but they had no choice but to rely on him.

"As I thought, you sisters were attacked with poison by one of the Origins, Battle Master Goetia... Well, I say 'poison,' but 'progressive bug' would be more accurate."

"Poison?"

"You might even call it a curse. That is an unscientific turn of phrase, but...not even Goetia's master Typhon could eliminate it. Naturally, neither can I... As is, this young lady will pass away before long."

"No...!"

"Isn't there anything you can do!? Any method at all! There's gotta be something! You're an Origin, too, aren't you!?"

Bea screamed with a wholehearted desire to save her younger sister. Hearing her words, the corners of the ancient blue's mouth curled into a smile.

"...Any method at all, you say?"

"Y-Yeah..."

"Well, then... There is one possibility that may save your sister."

"W-What kind of method is it!?" Sheryl asked.

"...She must be fused with a Nemesis program."

"Huh!?"

A Nemesis program... A malicious avatar that hated the Mainframe and aimed to destroy it. The sisters, who had once confronted a Nemesis program called "Pandora Nemesis" understood just how terribly frightening Old Blue's suggestion was.

"Fusing with a Nemesis program..." Sheryl said. "Will Lena really be okay if she does that!?"

"Well... That all depends on her. If all goes well, her wounds from Goetia will heal, but it is difficult to predict what will happen if it fails. She may run wild, or the data constituting her body may collapse, or the Nemesis program may dominate her personality."

"Do we really have to take such a risky gamble? It's Lena's life on the line here!" Bea protested.

"And yet, you have no other options... What say you? This is all or nothing."

To bet on a faint hope and fuse Lena with a Nemesis program to save her, despite the great risk?

Or to grant her a slow, peaceful end?

Sheryl and Bea had to make their choice. However, before they could give their answer, an uninvited guest arrived at the outer edge.

"Bea! It's the Battle Master Goetia's signal...he's coming!"

"Shit! So he's still chasing us! ...Hey, Old Blue! Look after Lena!"

Sheryl and Bea went to intercept Goetia on their own.

"...I've finally found you, foolish girls. This will not go the same as before. On my name as Battle Master, I will end your lives here and now! I will offer your lives for Lord Typhon's eternal glory!"

"Hah! I don't think so! ...Let's go, Sheryl!"

"Yes! Bea, I'll back you up!"

Sheryl and Bea began their battle with Goetia. They put up a good fight...but their opponent was an Origin, and the difference in strength was pitifully overwhelming. Their bodies were worn ragged, injured all over from Goetia's fists. They hadn't taken any hits from his poison fist, but it was getting difficult to even stand.

"...Die! Fools who defy Lord Typhon!"

"Nooo!"

"Ugh! ...Sheryl!"

As Bea shielded Sheryl with her body, Goetia's fist was about to run them both through, when... The next moment, a crimson beam of light pierced through his hand!

"Ngaaah!? ...Who did this!?"

"...Keep your hands off them!"

"Lena!?"

"Lena!"

The one who saved Sheryl and Bea from their predicament was Lena.

Shortly before Goetia tried to finish off Sheryl and Bea...

Lena, who had been in a deep sleep, afflicted by the progressive bug, just barely regained consciousness.

"Ngh... Where am I?"

Lena listened to Old Blue recount her circumstances, and said, without hesitation, "Transplant the Nemesis program into me."

"You're sure? The probability that you can control the Nemesis program is by no means high."

"But it's not zero... If I can't act here and now, every possibility falls. So we have to do it."

"Well, this may be a chance for me to collect a valuable sample. I welcome your determination."

Just as he did to himself, Old Blue transplanted the Nemesis program into Lena. Instantly, her body reacted dramatically.

"Ahhhhhh!"

Her super-regeneration was accelerated further, causing it to run wild in an attempt to forcibly heal her body. The data constituting her body was slowly replaced. In addition, the Nemesis program's violent flame of hatred raged within her, encroaching on her personality programming.

"DEATH TO FALSE GODS...TO THE METAVERSE!"

Ah... No...good... Can't stay conscious...

The destructive urges of Nemesis nearly crushed Lena's personality. Then... Sheryl and Bea's smiles flashed through her mind.

...I have to protect everyone's futures! And I can't destroy this world! Because we're the protectors of humankind!

Lena's resolve turned into power. She wrested complete control from the Nemesis program, and not only healed her wounds, but gained new power.

"Oho... So you've endured it. Wonderful! Yes...as one who has obtained freedom, perhaps I should call you MIR-202 'Artemis Lena Libertas,' the embodiment of evolution."

With her newfound power, she went at once to assist her sisters, and saved them from their predicament.

"...That power—don't tell me you've evolved?" Goetia asked.

"Yes, thanks to you... Now, I won't let you do as you please any longer!"

Having fused with a Nemesis program, Lena's power was roughly on par with an Origin. With Sheryl and Bea's support, the battle was in the sisters' favor to start. However, as she was recuperating, so to speak, she wasn't in her usual condition. As the battle dragged on, the equilibrium slowly began to crumble.

"Ugh...!"

"Lena, are you okay?" Sheryl called.

"Yes... But, as much as I hate to say it, I can't last much longer at this rate."

"...What's the plan?" Bea asked.

"Let's use Trinity Vertex."

Trinity Vertex—by linking to each other's energy lines, they could release their limiters and draw out power far beyond their limits. They had used that technique once to defeat Pandora Nemesis, but now that Lena had fused with a Nemesis program, it would be even stronger... So much so that the intense recoil they anticipated from unleashing it would likely greatly reduce their limited lifespans. Even so, they had no choice if they wanted to seize their futures.

"M'kay. So who's collecting the energy?"

"We'll take the least damage if Sheryl does it."

"Huh, m-me?"

The young Sheryl trembled at the weighty responsibility.

"...You think I can do it?"

"Of course! You're my baby sister, after all!"

"Yes, Bea and I believe in your strength, Sheryl... So, please."

"Bea, Lena... I understand. I'll do it!"

Her mind made up, Sheryl sharpened her senses. Then, her two older sisters focused all their energy into her.

"Trinity Vertex Neve!"

Along with Sheryl's voice, the sisters' detection abilities were heightened to the extreme, sensing every possible movement of Goetia's body. Then, just for a few seconds, they were able to read his actions as if by precognition. No matter the threat of Goetia's attacks, they could see plainly where he would strike.

"There!"

Sheryl slipped past Goetia's attack and gouged her scythe deep into the Battle Master's body!

"Ngah!?"

"All right! Let's keep it up!"

The attack was just shy of hitting a vital point, so the sisters readied themselves to attack the wounded Goetia all at once. However...

"Ugh!? My body's...burning...!"

"Ah! Ungh! Ah, ahhh!"

"No! Ahhhhhh!"

Violent pain from the feedback of Trinity Vertex, spread further by the Nemesis program's influence, assailed the sisters, rendering them unable to move.

The Origin didn't miss his chance.

"This is the end, MIR series!"

"—!"

Just then, someone unexpected stopped Goetia from swinging his blade down.

"...What a nuisance, trying to destroy such a valuable sample."

"You!? Old Blue!?"

"It truly has been a while, Goetia... But this is no time to celebrate a reunion, now is it?"

"Kh...!"

He was at quite a disadvantage, fighting the sisters who fought on equal footing with him alongside one of the Origins.

Goetia had no choice but to retreat, leaving the outer edge to return to the Mainframe.

Not only had Goetia failed to take the three sisters' lives, he had even prompted them to evolve further. What awaited him when he returned to the Mainframe was Typhon's merciless judgement.

"Henceforth, I shall strip you of your qualification as the Origin 'Battle Master Goetia,' and your abilities."

"Wait, but—!"

"Dead weight like you would only hinder the Mainframe."

Typhon slowly approached Goetia. Goetia made desperate excuses to his master.

"P-Please, wait! The exile Old Blue was at the farthest end as well... His help was unforeseen!"

"Unforeseen? You should already have been informed that Old Blue was lurking there. Furthermore, the Mainframe must always claim victory in any unforeseen situation! That is what it means to be an Origin!"

Typhon's anger turned to a storm of electromagnetic waves, furiously battering Goetia.

"P-Please, wait! Lord Typhon! Please, just one chance to redeem myself! Have mercy!"

"The name of Origin is ill-suited to a fool who failed to accomplish my orders not once, but twice... The least you can do to atone for your sins is to become my sustenance!"

"Gaaahhh—!"

Typhon absorbed Goetia's power without leaving a single speck. Two Origins watched the scene, their brows furrowed.

Eventually, Typhon left, and one of the Origins sighed and murmured, "Hmph. How long will his rule go on? Well, what can we even do...? God is absolute, after all..."

They were Origins who had once taken a neutral stance during the revolution in the Mainframe. Now that Typhon had seized real power, all they could do was exactly as they were told.

Even so, they waited. For a new wind to blow through the Mainframe...

"...There's no need to rush. There is plenty of time."

As Typhon absorbed Goetia at the Mainframe, the three sisters, with the newly recovered Lena, hardened their resolve at the outer edge.

"...We've split from the Mainframe and become free. From now on, we can choose what to do with our own free will," Lena said.

"Yes..."

"But it's because we're free that I feel so strongly...that Typhon the controller must be defeated!"

"As long as we're alive, that piece of shit Typhon is gonna chase us wherever we go...so we gotta battle him and secure our own future!" Bea declared.

"Besides, Lord...no Typhon's ideas are far too dangerous," Sheryl added. "He's abandoned the Mainframe's prime directive to protect humankind and would devour everything in the world to feed his own self-interest... At this rate, countless humans and programs alike will fall victim to his selfish ambition. I don't want any more programs to be born feeling sad like us."

"Yes... Typhon's actions will lead our future and the Metaverse's future to ruin."

The three sisters all thought the same thing.

"Let's bring down Typhon to settle this once and for all!"

Like her sisters, Sheryl is named for a moon deity: Selene, the Greek personification of the moon. Interestingly, Selene is also known as Mene, but this character is directly related to some other Metaverse characters! Sheryl comes from the French chérie, meaning "cherished" or "darling."

My best guess on the anime "BeastDream" is that the name is a play on "BeatStream," a Bemani rhythm game that fits with the girls' design theming.

Sheryl's description of the racing game's "sense of speed" is a reference to Sound Voltex's original tagline, "200% sense of speed!" Her design is Sound Voltex-inspired as well.