Crossover Shipgirls: Building a Dimensional Empire from Scratch

In the boundless sea of stars, the Astral Express broke through the barrier surrounding the Solar System and sailed toward the distant unknown.

”Ah...”

Inside the carriage.

Kiana, Mei, Bronya, and the other Valkyries pressed against the porthole, gazing at the brilliant river of stars outside.

It was their first time leaving their homeland to explore another world on their own. They were both excited and nervous.

”We are currently traveling through the void between two star regions. Estimated time to arrival at the target region is...”

Sophon’s figure was projected as well. As a higher-dimensional artificial intelligence, she could accompany any vessel and provide technical support to those aboard.

”What if we run into unfriendly aliens and have to fight? What if we meet bizarre-looking extraterrestrial creatures?”

”Uh... I remember the Starsea Empire’s textbooks saying that hostile alien civilizations are to be completely annihilated...”

Mei muttered to herself nervously.

”Let me repeat—our primary objective is exploration and expansion, not combat.”

Himeko cleared her throat.

”The vanguard team’s mission is to explore unknown star regions and establish connections with more intelligent alien civilizations.”

”As for any future battles or wars, those decisions will be made by the Commander and the Starsea Empire itself.”

”Oh...”

Mei thought about it.

Perhaps the Empire’s history books had simply described the fleet’s encounters with alien civilizations as a little too... militarily enthusiastic. Nearly every world they encountered had been beaten into submission.

The thought of representing the Starsea Empire on an expedition weighed heavily on her.

”Bronya understands. We are diplomatic personnel of the Starsea Empire.”

Bronya nodded.

”Like when playing a space strategy game—we’re the science ship sent out to explore the map. Mm, just with a bit of armament attached.”

”That’s the idea. This is the assignment for your extracurricular field practice.”

Himeko took a sip of red wine.

”Then what if we run into things like Dimensional Horrors or Ether Drakes—those science-ship killers?”

”There’s no such thing!!!”

The group erupted into playful chaos.

The Astral Express was fully equipped with all kinds of living facilities. Bronya tapped away at a holographic computer, recording data from their voyage.

Mei seriously reviewed the protocols for contact with alien civilizations. Kiana lay sprawled off to the side, mumbling in her sleep.

Whoosh—

They ate and drank along the way, admired the scenery during their free time, and recorded navigational coordinates.

Who knew how much time had passed.

Gradually, the dazzling clusters of stars beyond the window gave way to an endless stretch of deep space.

”The vessel is crossing a sparse nebula region. Consecutive jumps will commence shortly.”

Sophon and the ship’s AI issued a reminder.

From the star charts, the structure of the Honkai universe was completely different from that of other universes.

It resembled a collection of independent star regions and galaxies. Each galaxy could practically be regarded as its own world.

Boom!!—

The Astral Express trembled, and everyone felt a momentary distortion of space and time.

The scenery before their eyes compressed to an extreme—then expanded once more.

Though the Starsea Empire’s warp technology differed slightly from that of this universe, both ultimately achieved the same result.

After passing through a bizarre, kaleidoscopic corridor.

The train emerged into an unfamiliar star region.

Beep, beep, beep—

Almost simultaneously.

On the star map, the ship’s sensors reacted.

”Within a radius of one hundred light-years, a large number of intelligent alien civilization signatures have been detected.”

”!!!”

”Did we just arrive at another world packed with aliens?”

Everyone crowded around the main console.

”See? I told you—the Solar System was just too remote. Aliens probably couldn’t even find their way there.”

”Uh... the density of civilizations here is higher than I imagined...”

Himeko looked at the densely packed markers on the star map.

Each one represented signs of intelligent life detected by the sensors. It felt like stepping from a desolate countryside straight into a bustling city.

”Activating auto-translation system. Decoding language...”

”Confirmed. Six light-years away, there is a planet inhabited by an unfamiliar intelligent alien civilization.”

Sophon closed her eyes, performing trillions of analyses within moments.

”Preliminary assessment: humanoid lifeforms with high intelligence. Low hostility and low proactive aggression.”

”Huh? A planet?”

The group grew even more excited.

Humanoid intelligent life meant they were at least unlikely to be crazed beings who attacked on sight. There was room for dialogue.

”Then... should we go take a look? ...”

...

Hum... Boom!!—

The Astral Express performed another short-range jump.

When space gradually stabilized around them, they looked out from the carriage and saw an enormous object resembling a planet.

Its overall structure was like that of a colossal starship. Its size even surpassed Eternal Snowfall.

Yet its exterior lacked the cold severity of an Imperial flagship. There were no countless axial weapons or gun turrets.

Instead, it featured carved balustrades, jade-inlaid architecture, and sweeping eaves—somewhat reminiscent of Dragon Empery aesthetics. Combined with advanced technology, it formed an unmistakable cyber-oriental style.

Countless small vessels flew back and forth along its exterior. At the entrances and exits of the giant ship, enormous floating arrays shimmered faintly, seemingly used to isolate unwanted visitors.

To put it simply—Eternal Snowfall was a weapon of war, while this Xianzhou was a world unto itself, accommodating all things and sustaining daily life.

Hum...

The colossal ship moved slowly through space—though for an object of celestial scale, its speed was already astonishing.

”Is that... a planet-class battleship??!!”

Everyone aboard the Astral Express was stunned.

It was their first time witnessing a true extraterrestrial civilization of the space age.

Trisolarans, Zero-Homer, Cybertron—all those existed only in the Starsea Empire’s history books.

Seeing a planet-class vessel up close left no doubt that the other party possessed an extremely advanced technological level.

”They’re... a civilization living on a starship?”

Mei couldn’t help thinking of the Starship Earth described in textbooks.

[Beep—]

The Astral Express’ communication system activated.

The other party had initiated contact—a clear female voice rang out.

”Unknown flying unit detected. Identity verification failed.”

”This is the Xianzhou Alliance Luofu. State your identity and purpose.”

”!”

”We are—”

The white-haired paramecium was about to eagerly introduce herself when Himeko stopped her.

”We are an expedition team of the Starsea Empire, a vanguard unit and group of explorers from another star region.”

”Xianzhou Luofu—is that your name? We request temporary docking permission.”

”...”

There was a brief silence.

”Landing permission granted.”

”Welcome to Luofu’s Starskiff Haven. Please await escort.”

Hum—

A boat-like craft flew out from the Xianzhou, guiding the Astral Express toward an internal port.

”Please follow the starskiff for landing. All foreign visitors must complete identity registration first.”

”So that thing’s called a starskiff? What a poetic name...”

Kiana looked up at the vessels weaving through the air.

For the first time, she truly felt she was facing a genuine alien civilization.

”Remember—every word and action of ours represents the Starsea Empire. Don’t embarrass us.”

Himeko lightly tapped Kiana on the head.

”Oh!”

The white-haired girl immediately straightened her posture.

”The Jade Gate is opening...”

The internal checkpoint slowly opened, and the Astral Express docked in its berth.

”Whoa...”

Stepping onto solid ground, the scene before them suddenly opened up.

A broad road paved with green stone stretched straight ahead. Along it stood layers upon layers of buildings.

Pavilions rose high, embedded among cloud-wreathed mountain peaks. Roads extended in all directions. Crowds bustled about, and starskiffs arriving from afar continuously descended into the port.

Though it lacked the extreme sci-fi aesthetic of the Starsea Empire’s capital, Xianzhou Luofu’s architectural style offered a completely different sensation.

It blended classical elegance with an otherworldly grace, forming its own unique identity—as if heaven itself had shaped it.

The soldiers stationed along both sides wore dark ancient-style armor and held crescent-bladed halberds, looking imposing and dignified.

If not for the starskiffs constantly flying overhead, Kiana might have thought she had traveled back to ancient Dragon Empery.

Then she looked up.

A black-haired, green-eyed girl with fox ears and a flowing fox tail approached, accompanied by several Cloud Knights.

She wore a brown-and-red modified traditional outfit and held a folding fan. Her voice was crisp, with a trace of charm.

”Are you visitors from another world?”

”This humble one is Tingyun, receiving envoy of the Sky-Faring Commission’s merchant guild of Xianzhou Luofu. Among the myriad worlds of the cosmos, from whence do you hail?”

”Miss Tingyun, merchants and travelers are usually received by the Port Officials and Navigation Officers. Why are you personally—?”

The official beside her looked slightly surprised. Tingyun waved her fan lightly.

”I happened to glimpse this train and found it somewhat unusual. It does not resemble merchants from other worlds, nor does it seem like offworld drifters. So I thought I would come and take a look.”

”Mm... the galaxy stretches far and wide. May I ask where you hail from, and what brings you to the Luofu?”

Her gaze lingered on the Astral Express. The flag and emblem of the Starsea Empire were etched along the carriage exterior. Its construction faintly reminded Tingyun of another legend.

Ordinary merchants and seekers of medicine would not require her personal reception. Yet her intuition told her these visitors were far from simple.

”We are a vanguard team of the Starsea Empire, exploring new worlds and civilizations throughout the universe.”

”We happened upon the Xianzhou and wished to establish contact.”

Himeko inclined her head politely.

”Starsea... Empire?”

Tingyun closed her folding fan and rested it against her chin in thought.

”There is no record of you within the Whistling Flame Merchant Guild. I presume you have never visited the Luofu or the Xianzhou Alliance before. Might I ask where you originate?”

”Mm...”

Although Tingyun remained exceedingly courteous, Himeko still felt slightly uneasy about revealing their world outright.

After confirming once more with the space station, she opened the holographic star map.

”The Solar System.”

”Oh? Then you are honored guests from afar.”

Tingyun glanced at it, clapped her hands lightly, and offered a graceful bow.

”The Xianzhou has never traversed that star region, nor have merchants from there visited the Luofu. Mm... tell me, are there other worlds in that sector?”

”Please, follow me. Allow this humble one to play host.”

”...”

The group followed Tingyun through the starskiff docks, boarded a skiff, and swept past the bustling Xuanye Avenue.

Below them, shops stood shoulder to shoulder, lights burning day and night. Countless travelers seeking medicine, knowledge, and trade streamed endlessly into the Luofu.

As they traveled, Tingyun introduced the situation, while Sophon sifted through vast seas of information.

”In the ancient mythic era, nine Xianzhou ships set sail into the starsea under imperial command, seeking the elixir of immortality. After thousands of years, they finally received the blessing of the Aeon of Abundance.”

”Yet the fruit that granted immortality brought desolation to the four seas and suffering to the people. Only when the Aeon of the Hunt returned from the abyss—stringing gravity as a bow and drawing celestial arrows to full—was the Ambrosial Arbor severed, thus ending the scourge of Abundance.”

”After escaping their misguided path, the Xianzhou, guided by the Hunt, formed an alliance and organized the formidable Cloud Knights. Taking the abominations of Abundance as their beacon, they roam the boundless starfields to eradicate the corruption of immortality.”

”Xianzhou Luofu is one of the six remaining flagships of the Xianzhou Alliance, sailing the endless starsea to hunt the sworn enemy of the Lord of the Hunt.”

”Oh...”

The group listened, half understanding.

In essence, during ancient times an emperor had dispatched nine Xianzhou vessels in search of immortality. After millennia, they received the blessing of the Aeon of Abundance—the Merciful Medicus—and achieved their goal.

However, divine blessings were never without cost. Longevity created unforeseen social catastrophes. Only with the aid of another Aeon was the crisis turned back.

After years of war, six Xianzhou vessels remained. The Alliance now sails the eternal void, hunting the abominations of Abundance.

Each Xianzhou ship is an independent miniature world—akin to a celestial generational ark, somewhat reminiscent of Wandering Earth, though technologically superior and far more fantastical.

”Uh... why does this sound suspiciously like some Qin Shi Huang setting? I feel like our hyper-evolution surgeries and genetic ascension tech are way ahead...”

Kiana whispered to Mei.

In pursuit of immortality, the Starsea Empire had countless methods—genetic biotechnology, consuming spirit crystals to become Spirits, and much more.

If all else failed, they could even ask Ereshkigal for a favor and retrieve someone from the Underworld after death, achieving a perfect internal cycle.

”Ah, that may be so. But the Luofu is quite different from the Yaoqing. Since you have come here first, you truly chose well.”

Tingyun led them into a grand palace whose upturned eaves resembled a ship’s prow. Numerous navigators bustled about inside.

”This is the Divination Commission’s headquarters of the Sky-Faring Commission. All exchanges and trade with other species are handled by us.”

”Please, have a seat.”

With a warm smile, she guided them to their seats and ordered refreshments.

”...”

Himeko felt almost flattered.

Looking back at the Starsea Empire’s conquests, it was rare to encounter a civilization that engaged in proper diplomatic etiquette.

Either they were lunatics like the Trisolarans or Singers who attacked on sight, or primitive worlds with little value for communication.

Formal diplomacy between civilizations was exceedingly uncommon.

Of course, another reason was that Setsuna and the Starsea fleet had not come in person. Otherwise, at the sight of Juggernaut, few would remain calm.

”Ahem—”

After exchanging pleasantries, Tingyun displayed great curiosity about the Starsea Empire’s origin.

She even posed several rather peculiar questions.

”May I ask—which Aeon does the Starsea Empire revere? Mm... you do not appear connected to the Reignbow Arbiter. Since you have journeyed across the starsea, could it be the Cloudweaver?”

”Or perhaps the Aeon of Elation, or the Aeon of Erudition? ...”

”Uh...”

Himeko looked awkward.

”We are not governed by Aeons over there. If we must say, some people worship Eris and the like. There are also several Venusian goddesses and Underworld goddesses...”

”Oh?”

Tingyun’s interest deepened as she studied them.

”Fascinating... I imagine the Master Diviner would find you most intriguing.”

”Since you hail from another world, do you intend to establish trade with the Luofu? If you wish to engage with the Xianzhou Alliance, this humble one would be happy to assist.”

”It would allow me to witness for myself what remarkable treasures the Starsea Empire possesses.”

As expected of the chief representative of a merchant guild, her tone was impeccably pleasant.

”Mm...”

”We are merely a vanguard exploration team. Major agreements must be decided by the Commander.”

Himeko answered honestly.

”Oh? Then you should report your findings to your superior at once.”

Tingyun smiled and summoned several officials of the Sky-Faring Commission.

”If you do not mind, I can arrange accommodations for you on the Luofu. As it happens, I have some leisure these days. I would be delighted to guide you through the Xianzhou’s customs and scenery, and we may discuss matters further.”

”This humble one truly looks forward to seeing more of the cosmos’s wonders and hearing the universe’s tales.”

...

Later that evening.

Under Tingyun’s arrangements, the Astral Express group temporarily resided within Starskiff Haven.

”Wow, these aliens are actually really nice—”

Kiana lay on the sofa, munching on snacks while observing the room’s decor.

It felt both familiar and unfamiliar, reminding her once again of the Dragon Empery shipgirls like Yat Sen and Chen Hai.

”It’s great that we didn’t get attacked on sight or put on a wanted list the moment we landed—”

”By the way, aren’t they technically human?”

”Strictly speaking, they belong to the primate order, hominidae family.”

Bronya replied expressionlessly while browsing data.

”The Miss Tingyun who received us should belong to the Foxian race—a canine subtype within hominidae.”

”There is also the Vidyadhara dragon lineage subtype, though we did not encounter them today. Therefore, from our perspective, they are aliens.”

”...”

Himeko opened the holographic interface and seriously reported their situation to the space station and Setsuna.

”Report. We have deviated from the predetermined route and encountered our first intelligent alien civilization. They call themselves the Xianzhou Alliance...”

”Whoa...”

The little loli at the space station listened in admiration.

”A planet-class generational ark! It must be a fusion of magic and technology, right?”

”Mm... I really want to go up and conduct field research...”

”So you ran straight to the Xianzhou first?”

Setsuna chuckled.

”Not bad. Check their timeline.”

”Hm?”

Himeko glanced over. The Xianzhou had its own calendar system.

”Year 8099 of the Star Calendar, ninth month.”

”Oh. Then there are still a few months before the Stellaron’s birth, the Antimatter Legion’s raid on the Herta Space Station, and the Luofu Stellaron crisis. You can explore a bit more. No rush. You can also prepare in advance.”

Setsuna thought for a moment.

At least this ensured that Tingyun would not suddenly tilt her head in a sinister fashion at them later.

”Then our relations with the Xianzhou? ...”

”Peaceful exchange. You can also take this opportunity to look around. Don’t treat me like some space green-skin who sends a fleet to fight first and ask questions later.”

Setsuna laughed.

”Also, the key here lies with the Aeons—the Reignbow Arbiter and the various Aeons Tingyun mentioned. It’s another entirely new power system. Interesting.”

Beside him, Gudako read through the materials, muttering to herself.

”Aeons ascend from intelligent lifeforms. They are highly condensed embodiments of philosophical concepts...”

”The Commander will definitely become an Aeon one day. His manifestation would be...”

She turned to look at Setsuna, her face suddenly filled with horror.

”Uh... the Party Aeon?!”