Crossover Shipgirls: Building a Dimensional Empire from Scratch

Boom!!

The Eternal Snowfall engaged its thrusters, slowly departing from the Starbase.

The entire dock seemed to tremble slightly.

With the starship freshly upgraded, of course it needed to take a spin.

Everyone stood on the vast bridge at the top, gazing out the portholes at the endless weapon wings stretching out on both sides.

Cold and lethal weapons lined them, reflecting a dark gleam in the void.

Setsuna felt the overwhelming power of the Juggernaut.

He and the Eternal Snowfall were one; in a sense, the starship was his own lifebar.

Right now, that lifebar was thousands of times greater than before.

Despite the Juggernaut’s size, operating it while merged was not particularly complicated.

It only required some time to familiarize himself with the starship’s equipment.

Most actions could be executed with thought alone, and Grey, Observer, and the other builders were there to explain everything on-site.

Shwoom—

From the starship’s stern, a tail flame hundreds of kilometers long erupted as it began to accelerate.

Passing Earth’s outer edge, it was nighttime.

In the capital, people looked up, spotting the giant with the naked eye.

As it passed between the Earth and Moon, it even caused an effect like a lunar eclipse.

The surrounding starlight was blocked as well.

If not for the starship’s anti-gravity system, its mere proximity to Earth would have caused gravitational anomalies.

”Is that the trainer… no, the Commander?”

Special Week, Tokai Teio, Oguri Cap, and other Horse Girls training on the track raised their heads, eyes wide with uncertainty.

They didn’t know much about high technology, but they could instinctively feel the starship’s might.

In the school dorms, chattering little lolis climbed out of bed to peer through the windows.

”Onii-chan! Onii-chan’s got a new ship!!!”

”I wanna go play on it…”

Azur Lane, Arpeggio, and Kancolle shipgirls in several ports also erupted in excitement, manifesting their ship forms and shooting into the sky one after another—wanting to see with their own eyes what had become of the Empire’s flagship.

”Ah, little Setsuna, that’s really something… No, I guess now I should call him ’Grand Setsuna,’ huh?”

The dragon girl Lucoa stepped out of the Imperial Library, opening her eyes slightly to deliver a corny joke, then gazed thoughtfully at the sky.

”Mmm, I overslept today—I should probably go have a look… nah, I’ll just wait until he gets back…”

Vmmm—

Its immense size did nothing to slow the Juggernaut’s acceleration.

In just a few minutes, traveling at sublight speed, the starship reached the edge of the Sun’s gravity well.

”Commander, want to try the Eternal Snowfall’s real main cannon?”

Observer sat on her tentacle rigging, licking her lips with a look of anticipation.

”We designed it together with Grey—this thing will scare the Arbitrators to death someday, hehe…”

”Oh?”

Setsuna selected the main cannon from the control console.

[Fallen Star Lance]

[Target not locked, weapon not ready]

[Charging: 0%]

[Power setting: 50% (Not Overloaded)]

”Huh?”

He found that the weapon’s output could be set anywhere from a 10% energy-saving mode to an overloaded 300% state.

”The Fallen Star Lance is powered directly by the Wisdom Cube, dark matter reactor, and the Allspark. Combined, their theoretical energy is close to infinite—but for safety, only a small portion is drawn each time,” Grey explained in simple terms.

”The stronger you are, the more power you can draw to fire the Fallen Star Lance. If necessary, you can even temporarily overload it for an even more powerful strike.”

Setsuna nodded in understanding.

”Alright, let’s give it a try.”

Humm—

The moment charging began, the entire starship gave a slight tremor.

Unimaginable energy gathered in the Eternal Snowfall’s main-axis emitter, the bow blazing with an orange light brighter than a star.

”Don’t hit the Sun!! And no planets in the Solar System either!!! One shot and we’re done for!!” Observer shouted.

”I know.”

Setsuna brought up the star map, compared it to the night sky above, and selected a remote system about thirty light-years away—Alpha Boötis. Scans showed it to be uninhabited and worthless for development.

[Charging: 97%, 98%... 100%]

[Target Locked]

Blazing energy compressed, warped, and roiled inside the main cannon.

He pressed the fire control.

BOOM!!!

A crimson energy torrent nearly a hundred kilometers wide erupted from the cannon’s muzzle, tearing through the darkness of space.

[Alert! Alert! Intense high-energy reaction detected!!!]

Sensors aboard every shipgirl went into a frenzy.

The Fallen Star Lance traveled faster than light. In interstellar warfare, one needed to strike instantly—whether it was a tachyon light spear or focused arc.

From the Solar System to Alpha Boötis was about 36 light-years. Yet only seconds after firing, the projection on the holostar map changed.

The Fallen Star Lance slammed directly into Alpha Boötis’s star, Arcturus. The star’s surface was torn open, triggering an explosion more violent than a supernova, obliterating the entire system.

The scattered stellar matter collapsed under its own gravity into a small black hole, plunging the system into darkness and silence.

On the star map, one less star system remained.

”...”

All this was visible through the FTL sensors.

From firing to destruction, only seconds had passed.

Yet overhead, Arcturus still shone—that light had left the star 36 years ago. It would take 36 years for Earth to see the star’s death with the naked eye.

”This…”

Realizing what had just happened, the shipgirls, Heroic Spirits, and companions watching swallowed hard.

The Eternal Snowfall could annihilate an entire star system on an astronomical scale.

And it was an instant strike.

No reaction time; the moment it fired, the target system was already gone.

Defending against such a weapon was a fantasy.

”Commander Onii-chan… what was the Fallen Star Lance’s output just now?”

Unicorn clutched her clothes timidly. If she weren’t Setsuna’s oathbound ship, she might have burst into tears.

”Default, fifty percent,” Setsuna replied casually.

”Grey, Observer, Kayo Senju—you’ve done well. I’m very pleased with the Eternal Snowfall and the new weapon you’ve created, the Fallen Star Lance.”

”This weapon truly lives up to its name.”

He could tell Grey’s earlier claim—that the Fallen Star Lance would one day have the power to destroy entire star clusters—was no exaggeration.

Any intelligent spacefaring civilization would understand its horror.

Shattering planets, extinguishing suns, annihilating stars—the lance high above the dome always kept its edge, while the rest could only pray it never descended.

The sword of annihilation hung high; the ants could only kneel.

...

”After a year on standby, I can finally move again… come on, let’s go fight aliens.”

...

Vmmm—

After completing its trial voyage, the Eternal Snowfall returned from the outer edge of the Solar System.

It slowly entered Earth’s orbit, becoming one of the planet’s satellites.

From the capital, looking up, there were now two moons.

One was the original silver-white Moon, the other—larger than the Moon by a noticeable margin—was the starship, reflecting starlight.

A ship of such colossal size could not possibly land near the capital.

Nor could its true body be manifested on the ground; otherwise, it would have an asteroid-impact effect.

Considering how troublesome it would be to move it in and out of storage, Setsuna simply kept the Eternal Snowfall in anti-gravity mode, waiting in Earth’s outer orbit.

Shwoom—Shwoom—

No sooner had it entered orbit than hundreds of shipgirls arrived in their ship forms, breaking through the atmosphere and drawing close.

”Commander~ Let us tour your new ship body, pleeease!!!”

Whether from Azur Lane, Arpeggio, or Kancolle, all the shipgirls were deeply curious about this planet-sized behemoth.

Their ships carried along little lolis, Heroic Spirits, Catgirls, Horse Girls, and a whole crowd of companions eager to watch the excitement.

”Alright, alright.”

Unable to resist the shipgirls’ pleading, Setsuna opened the lower hangar doors, allowing hundreds of starships to dock one by one.

Inside, the planetary-class Juggernaut was modeled after a Starbase, complete with berths for docking.

Even when the three port-area shipgirls docked their carriers, battleships, and other large vessels, the place still felt spacious.

When these ships visited other worlds and bullied the locals, their tens-of-kilometers-long hulls often cast shadows large enough to blanket a city.

Before the Eternal Snowfall, they were tiny specks.

The Juggernaut’s shadow in space could cover an entire planet.

If it appeared in the Earth-Sun orbit during the day, a single ship could block sunlight entirely.

”Mmm, I used to think the Yamato-class battleship was the biggest and strongest in the world—guess I was a frog in a well.”

Yamato jumped down from her hull, tidied her hair, and sighed from the heart.

”Compared to the Commander, I’m like a carrier’s onboard plane.”

”Being with a commander like this… it feels so safe.”

Shoukaku shared Yat Sen’s sentiment.

The Juggernaut’s size was terrifying, but knowing it was the Commander’s ship put the shipgirls at ease.

It felt as if, as long as they stayed here, the Eternal Snowfall would shield them from any danger.

The visitors boarded shuttles in groups, traveling into the cylindrical internal corridors.

Within the 3,600-kilometer-long starship, a vast transportation network—akin to a highway system—was built.

The shuttles accelerated to dozens of times the speed of sound, occasionally engaging short-range warp jumps.

It took some time before they reached the ship’s upper bridge.

”Woah…”

Heroic Spirits, Spirits, and little lolis looked around like children on a school field trip to an aircraft carrier.

Everything was new and fascinating.

No one had imagined that simply moving around inside a starship would require supersonic shuttles.

”So many people? Is this a summer camp?”

Setsuna laughed as he watched the bustling, chattering crowd.

Some of his companions seemed even more concerned about the Eternal Snowfall’s condition than he was.

”Come on, feel free to look around.”

He led everyone on a tour inside the ship.

In addition to countless weapon modules, the living areas of the starship were equally astonishing in scale.

As an immense mobile space fortress, the Eternal Snowfall’s interior was built to the standards of a city.

Its living quarters were as large as the Moon’s colonies.

”A hydroponic farm?! Commander, your ship has a hydroponic farm?!”

”An industrial zone?! Huh? You actually have separate industrial and agricultural zones inside the ship?!”

Down in the lower decks, the shipgirls were amazed to find sizable agricultural and industrial areas.

In the greenhouse hydroponic farms, the Angeloid moved about, fertilizing crops and monitoring data.

The metal smelting plants had everything from mineral refining to advanced processing lines.

Aside from the docks being able to produce starships, most light industrial and manufacturing products could be produced onboard.

”The Juggernaut was designed to support a fleet in ultra-long-range expeditions,” Kayo Senju said proudly, introducing her work.

”Even without any external resupply, the internal circulation system can sustain a million crew members for thousands of years.”

”Considering that shipgirls and Heroic Spirits don’t need to eat much, that time could be extended even further. If necessary, the Eternal Snowfall could evacuate everyone in the capital.”

”...”

In the vastness of space, distances between galaxy clusters are often measured in hundreds of millions of light-years.

Even with FTL drives, expeditions beyond the Milky Way could take hundreds or thousands of years.

Conventional fleets struggle to cross the tens-of-thousands-of-light-years of empty void between clusters—regions without stars, planets, or any chance of resupply.

Only the Juggernaut could support an entire fleet through such journeys.

”So we could go even farther in the future? The Andromeda Galaxy? Perseus?”

The shipgirls suddenly realized their range had greatly expanded.

”Yes. When there’s time, we can visit beyond the Milky Way,” Setsuna nodded.

Beyond standard industrial and agricultural modules, the ship also housed luxurious entertainment and living facilities—massive artificial hot springs, a holocinema, indoor stadiums, and more.

Without being told, one would hardly guess they were inside a spaceship.

”It feels like a miniature version of the capital,” Illustrious, Belfast, and several shipgirls murmured, feeling a strange dissonance.

If one stayed in the living area and ignored the weapon modules, it was like living in a mobile space city.

”Of course, you’re all welcome to come here anytime for vacation or sightseeing—the Eternal Snowfall is plenty big,” Setsuna said with a smile.

”Wait, Commander—you can warp time, can’t you?…”

Gudako thought for a moment, then slapped her thigh.

”Before, you warped time inside a single starship. Now that the Eternal Snowfall is this big, wouldn’t that be like changing the flow of time for an entire planet?!”

Time acceleration and deceleration skills were extremely difficult to master, and Setsuna had barely learned to warp his own time.

But using the ship-body merger trick, he could treat the hull as an extension of himself.

Now, with the Eternal Snowfall’s massive size, even Tohru or Lucoa couldn’t warp the time of an entire planet—but he could, because the ship was his body.

”Let’s try it.”

Setsuna closed his eyes and reached out a hand.

”Self Time Warp—120x.”

Crack—

Space trembled slightly.

The slowly rotating Earth beneath them nearly froze in place under the massive time dilation.

Now, one hour outside was equal to five days aboard the Eternal Snowfall.

Previously, the more people on the ship, the harder time-warping became.

But with the Allspark providing him energy, controlling time seemed easier.

Many little lolis and shipgirls, seeing time warp for the first time, crowded by the portholes, chattering excitedly.

”Mmm… vacations aboard the Eternal Snowfall will be much nicer now,” Setsuna mused.

”There’s so much space and so many facilities—we could easily spend a month or two without getting bored…”

He glanced over. ”Yat Sen, Richelieu, Belfast, Mio, Nagato… want to try spending the night here?”

”Ah…”

His harem blushed.

A ’single night’ under self-time dilation could stretch into over a month.

After each triumphant return from an expedition, Setsuna always celebrated in style.

Unicorn, who had never experienced it, looked at him curiously.

”Onii-chan, is everyone staying here tonight? Will you spend more time with Unicorn?…”

”Wha!!!”

Gudako jumped.

”Commander, before your ship was called the Eternal Silver Party—now that it’s a Juggernaut, is it the Eternal Super Big Silver Party?!!”

—

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