Crossover Shipgirls: Building a Dimensional Empire from Scratch

”Hmm... the experiment turned out even better than expected...”

After little Kiana’s birth, the Life Sciences Division conducted a series of basic examinations.

”Her fusion with the Herrscher Core of the Void is flawless. Unlike the original, which used an incomplete core, the one within her is a fully intact version.”

”Moreover, her body exhibits extremely high adaptability to Honkai energy. Once she matures, surpassing S-rank Valkyrie level will be effortless—and she’ll likely gain full control over the Herrscher of the Void’s power.”

”If we go further with genetic ascension and hyper-mutation surgery... hmm, I’d say she could become the strongest Valkyrie—without question.”

On the holographic display, Kiana’s vitals and energy metrics were displayed in perfect harmony—the result of meticulous optimization by the researchers. Her condition was nothing short of ideal.

”As for the Herrscher personality awakening... we can probably deal with that later, either by separating the residual consciousness or letting her handle it herself.”

Kayo Senju scratched her head again.

”After all, in the original story, Kiana’s Herrscher personality awakened because of loneliness and her longing for a mother’s love. But in this timeline... that’s not likely to happen, right?”

As she spoke, she glanced at Cecilia.

”Power doesn’t matter. As long as she can grow up happily, that’s all that matters.”

Cecilia smiled and gently pinched Kiana’s cheek while holding her in her arms.

”...You’re already addicted to motherhood, aren’t you...”

Setsuna chuckled to himself.

Whether Kiana chose to become an ordinary Valkyrie, the Herrscher of the Void, or even the Herrscher of Finality like in the original story—it didn’t matter.

It was entirely up to her. No matter which path she took, he could support her all the way.

”Oh, right, one more thing. Let’s have Kiana stay on the space station for now. We’ll need to observe and monitor her condition closely.”

Grey added at the end.

”We’ve never experimented with fusing a Herrscher Core into an artificial human before, so we need to make sure her growth and development are stable.”

”Also, we’d like to perform a comparative analysis between her and the Herrscher of the Void—we’re planning to attempt a replication of the Herrscher Core...”

”Oh?”

Setsuna’s eyes lit up.

”Replication of the Herrscher Core? You’re thinking of mass-producing Herrschers?!”

”Hmm... it’s difficult, but not impossible. We’ve already conducted high-precision scans of both the Herrscher of the Void and Herrscher of Reason cores.”

The research loli projected massive datasets onto the holographic screen.

”The challenge lies in reconstructing the Honkai energy lattice. We don’t expect to replicate the full imaginary-space linkage of the original Herrscher Cores—just simplified versions capable of mimicking basic authority.”

”Think of it as... a Divine Key, but in core form.”

”Good. Interesting.”

Setsuna nodded.

If they could truly mass-produce Herrscher Cores, that would be remarkable.

He could give one to Sirin, and once the Herrscher of the Void finished her ’training,’ she’d get one too.

Three generations of the Herrscher of the Void—all in one place. Triple the fun.

...

To little Kiana, everything on the space station was completely new.

She had no childhood memories—when she first opened her eyes, the first person she saw was Cecilia, whose gentle and motherly aura instinctively drew out the word Mama.

And naturally, Setsuna became her father.

”Mama, Mama, where are we~?”

”What is this place?”

The white-haired bundle of energy held Cecilia’s hand, wandering curiously through the halls of the space station.

She wasn’t shy at all—partly because her mother was by her side, and partly because the station was full of little girls just slightly older than her.

They all looked kind and approachable.

”This is the Starsea Empire. And this place is our space station...”

Cecilia explained patiently.

”Starsea Empire? Space station?”

”And that big sister—why does she have wings?”

Little Kiana kept firing off question after question, eyes wide with wonder.

”Uh... looks like we’ll need to start with some basic education...”

Cecilia realized that although the Life Sciences Division had created Kiana in a child’s form—complete with language and basic motor skills—her actual knowledge was absolutely zero.

”Come on, I’ll teach you...”

Cecilia led her by the hand, explaining as they walked, looking every bit like a mother taking her daughter to the park.

From the research labs, they wandered to the living quarters, then to the recreation deck. After dinner, they continued toward the administrative sector.

Kiana listened attentively, sometimes tilting her head, sometimes pressing her face against the window, staring in awe at the starry expanse outside.

Even though Cecilia spoke as simply as possible, most of it went far over the little girl’s head. But Kiana didn’t mind—she simply enjoyed the warmth of her mother’s presence, instinctively staying close.

”Ah, so wholesome...”

Setsuna couldn’t help but sigh softly.

It reminded him of the early days of creating shipgirls—when the older ones would take the little ones out to explore the capital together.

”Commander, you should spend time with her too. Kiana calls you Papa, remember?”

Cecilia brought little Kiana to the bridge.

”Oh...”

The white-haired bundle of fluff looked up.

At the main console sat Setsuna, his posture straight and commanding—so different from Cecilia’s gentle warmth.

”Papa...”

Kiana stumbled forward, tugging at the edge of his coat.

”Oh.”

Setsuna picked her up, pinching her cheeks and ruffling her hair.

”So cute.”

”...”

The white-haired bundle of energy looked up at the star maps spread across the console, then blinked her big blue eyes.

”Papa, Mama, will you tell me a story?”

”Hmm...”

How could he say no to that?

Fortunately, Setsuna had plenty of experience dealing with lolis. He pulled out a storybook, opened it on the desk, and began reading while holding Kiana in his lap.

”Hmm... this one’s from the DITF world, edited a bit by Grey.”

”Once upon a time, a demon princess lost her way in a human kingdom... and fell in love with a human prince...”

Kiana listened with sparkling eyes, completely absorbed. Formidable, watching nearby, tugged at her hair in envy.

”Ugh, if only I’d brought little Formidable along... we could’ve strengthened our ’family bonds’ with the Commander too...”

”Indeed...”

Illustrious nodded in agreement.

”Hmm...”

As the story went on, Kiana suddenly tilted her head and looked between Setsuna and Cecilia.

”Papa, Mama, did you two have a fight?”

”Huh?”

Both Setsuna and Cecilia froze.

”You’re sitting so far apart—it’s not like the mommies and daddies in the book.”

The white-haired girl pointed at the illustration, puffing her cheeks.

Then she grabbed both their hands and pressed them together.

”If you fought, you should make up quickly.”

”Eh?!—Eh?!—”

Before Setsuna could react, Cecilia’s face flushed bright red.

”N-no, it’s not like that, it’s just...”

She looked at Kiana’s innocent expression and couldn’t bring herself to shatter the little girl’s pure, childlike fantasy.

”Hmm...”

Setsuna simply wrapped one arm around Cecilia and the other around Kiana, pulling them both close.

”See? We’re fine. We get along very well.”

”Mm~”

Kiana nodded happily.

Turning another page, she saw an illustration of the prince and princess sharing a kiss.

”Papa, have you kissed Mama before?”

She asked with the utmost innocence.

”No—”

Cecilia’s face grew even redder, about to protest—when Setsuna suddenly replied calmly,

”Of course.”

He leaned over and planted a gentle kiss on Cecilia’s cheek.

”Mmh...”

Kiana beamed, certain that her parents had fully made up.

”C-Commander... you took advantage of me...”

Cecilia whispered, secretly pinching his waist, her eyes shy yet faintly resentful.

”...”

Setsuna didn’t mind at all.

”Good job, Kiana.”

...

”Kiana, Sirin, good night.”

”Ich liebe dich~”

After a full day of energetic activity around the space station, Kiana and Sirin finally fell into deep sleep.

The newly born little girl’s curiosity seemed endless. She clung to Setsuna and Cecilia all day, asking countless questions about the Starsea Empire and everything around her.

Taking her limited understanding into account, Setsuna explained things as simply as possible—only in terms she could grasp.

Even so, exploring an entire space station the size of a city exhausted her tiny body.

Before long, little Kiana was curled up under her blanket, drifting into sweet dreams.

”Phew—”

”Raising a normal kid really is different from taking care of shipgirls.”

Setsuna sighed softly.

Shipgirls were born from Wisdom Cubes, inheriting memories and instinctive knowledge of ship operations. Kiana, however, was a blank slate—everything had to be taught from scratch.

”Mmph...”

When she was sure Kiana and Sirin were sound asleep, Cecilia quietly closed the door, puffed out her cheeks, crossed her arms, and glared at Setsuna.

”Commander! You took advantage of me so many times today!”

In Kiana’s understanding, Setsuna and Cecilia were her parents. So Setsuna had simply gone along with it—hugs, hand-holding, even feeding her alongside Cecilia had become daily occurrences.

For the pure-hearted Cecilia, it was... a lot.

”Weren’t you the one who agreed to be Kiana’s mom? Between husband and wife, isn’t this perfectly normal?”

Setsuna teased with a grin.

”Hey!!—”

Cecilia pinched his arm hard.

”You pervert! You... you lecher!”

She had been raised as a noble lady from the Schariac family and barely knew any curse words—so when she tried to scold him, it only sounded like shy pouting to his ears.

”You didn’t exactly push me away though, did you?”

Setsuna pinched her cheek lightly.

Cecilia’s face flushed, her youthful beauty tinged with that delicate awkwardness only young girls had—though the faint glow of maternal warmth around her made her seem even more radiant.

”Th-that was... for Kiana’s sake!”

She looked down, voice quivering.

”If she ever thought her parents didn’t get along, it’d be bad for her development, right? So... so... I just went along with it! That’s all!”

Pfft—

Setsuna couldn’t help but chuckle at her flustered expression.

”Come on, I’ll show you something.”

He took her hand and led her to the outer ring of the space station.

Whirr—

The colossal silhouette of the Eternal Snowfall appeared in a holographic projection—its form majestic and awe-inspiring.

Since arriving in the Honkai world, Setsuna had mostly operated in superdimensional starship mode and hadn’t once manifested the Juggernaut’s full form.

”Huh? This is...?”

Cecilia stared at the planet-sized warship in stunned awe.

”This is the real Eternal Snowfall.”

Setsuna snapped his fingers, and a shuttle craft docked in front of them.

”You’ve wanted to see what’s out there, haven’t you? Come on—I’ll take you to see the universe.”

”Ah...”

Cecilia’s mind went blank for a moment.

As a member of the Schariac family, she had spent most of her life bound to Schicksal—sacrificing her freedom for her family. She had rarely been allowed to leave.

Even setting foot on a space station and seeing the vastness of the stars was already beyond what she had ever imagined.

Now, a man stood before her, offering to take her on a journey through the galaxy aboard a grand interstellar warship. What woman could possibly refuse?

”C-Commander... please, lead the way...”

She extended her hand, and Setsuna helped her aboard the shuttle.

Roar—

The starship’s engines ignited, humming as it departed from the station.

”Ah, I knew it. Commander’s off to charm the mother-in-law again. No way he’d fire up the Eternal Silver Party for no reason.”

Nearby, Grey scratched her head mid-task.

”Eternal what now? Why such a strange name?”

Kallen and Cheng Lixue exchanged puzzled looks.

”You’ll understand once you’ve been aboard, trust me.”

...

”It’s huge—”

The moment Cecilia stepped into the Eternal Snowfall, she was completely stunned.

If the space station could be considered a floating city, then this was nothing less than an entire planet.

The warship’s weaponized wings stretched for thousands of kilometers, but even ignoring those, the sheer scale of the ship’s core living area was immense—so vast that traveling inside required small personal aircraft.

Otherwise, walking from one section to another would be like crossing the lunar poles on foot.

”Pick anywhere you want to go.”

Whoosh—

Setsuna projected a starmap before her.

”Anywhere within two thousand light-years—we can jump there in one warp.”

”Farther than that... still doable, just takes a little more time.”

”Oh...”

Cecilia’s eyes widened, dazzled by the swirling constellations and glowing planetary icons before her.

On Earth, even with all of Schicksal’s technology, humanity had only just begun dreaming of interstellar travel. Compared to the Starsea Empire’s ability to leap across thousands of light-years in a single jump, the gap was immeasurable.

”I remember Schicksal’s scientists once saying it was nearly impossible to leave the solar system...”

She recalled aloud.

”That’s true—for the locals here, it’s practically impossible.”

Setsuna chuckled and zoomed the map out, revealing the massive structure of the solar system.

The Honkai World’s solar system was far larger than most universes’ standard models—something he’d already confirmed centuries ago when salvaging Griseo’s Ark.

”The outer boundary of the system is surrounded by tides of imaginary energy, forming a spatial barrier. Using normal propulsion to cross it is pointless.”

”But then again... what do you think our warp engines are for? Dark matter reactors, courtesy of the Fallen Empire’s technology.”

”Oh...”

Cecilia nodded slightly, not fully understanding but fascinated nonetheless. She randomly pointed to a location on the starmap.

”Then... there!”

”Hold on tight.”

BOOM—

With a thunderous crack, space itself shattered.

The view before them compressed into a single point, then expanded violently.

When Cecilia opened her eyes again, they were surrounded by a breathtaking sea of stars.

”Wow...”

She stared out the window in awe.

”It’s beautiful...”

In her twenty years of life under Schicksal, she had never once seen the world beyond Earth.

It felt like a caged bird had finally been released into the endless sky of the universe.

”Come on.”

Setsuna took her hand and led her up to the ship’s highest observation deck.

Protected by powerful shields, they could stand in open space without issue.

Above them stretched a canvas of starlight—constellations glittered across the void, and now and then, a meteor trailed a long, luminous tail across the heavens.

”Ah...”

Cecilia was transfixed, her mind blank, unaware that Setsuna had gently wrapped an arm around her shoulders.

”You... you can truly travel freely among the stars... how wonderful...”

She spoke softly, genuine admiration in her voice.

”When I was still with Schicksal, my days were filled with Valkyrie training and family duties...”

”Sometimes I’d look at the stars and wonder when Schicksal might build a ship to take me up there to see them. I never imagined you would make that dream come true for me.”

Her voice trembled faintly with emotion.

”This is just the beginning.”

Setsuna gestured toward the vast starfield ahead.

”Every visible universe—every star you can see—will one day be part of the Empire’s domain.”

”The Starsea Empire spans dozens of universes, each filled with countless galaxies waiting for you to explore.”

”Ah...”

Cecilia’s breath caught.

On Earth, among all the noble heirs of Schicksal’s families, there had been many exceptional men. She had long been destined, as the Saintess of the Schariac family, to enter an arranged marriage with a Kaslana or an Apocalypis heir.

But now, she realized that none of those men—none of them—could compare.

Their eyes saw only families, factions, and maybe humanity or Earth if they were ambitious.

But not a single one of them carried such overwhelming vision and courage.

To conquer every universe—to claim every star in the cosmos—what could be more breathtakingly romantic than that?

”...There are so many places... I could never visit them all...”

—

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