Crossover Shipgirls: Building a Dimensional Empire from Scratch

Stunned, astonished, bewildered…

People realized that the man before them, in just a few words, had decided the fate of two civilizations.

Like a lofty judge passing sentence.

And the conditions he proposed were, to humanity, nothing short of absurd.

”….”

After a brief silence, what followed was a wave of outrage sweeping across the world.

”You want us to surrender to the Starsea Empire?!”

”And abandon all dignity, becoming your vassals?!”

Human officials challenged Setsuna.

”No—you don’t even qualify to be vassals.”

Setsuna corrected them.

”I don’t care about your survival. I only care about certain things in this universe. The Solar System can remain as a forward base.”

”You can live under pre-space-age conditions. As long as you don’t cause me trouble, I’ll make sure you have food.”

”Too much!”

Humans on Earth, watching the live-broadcast negotiations, erupted.

”You’re treating us like lab rats! This is unfair!”

”This is tyranny and oppression!!!”

”Hegemony! Disgusting, revolting hegemony!!!”

Some furiously cursed at Setsuna’s holographic image.

Others clung to faint hope, trying to reason with him:

”We should build friendly cooperation! Think about it—if our two worlds coexisted peacefully, if our people could migrate freely between universes…”

”Shut up.”

Grey swore bluntly.

”You pests still dreaming of coming to the capital?! The Commander hasn’t neutron-swept you already—that’s mercy!”

”???”

Soon, Earth erupted in a storm of curses against the Eternal Snowfall.

They seemed ready to spit the ship out of orbit with sheer outrage.

After the Second Renaissance, humanity had adopted the slogan: Give civilization to years, not years to civilization.

Freedom, democracy, and such ideals had become universal values. To them, interstellar hegemony was unacceptable.

At UN Headquarters—

Sai quickly convened officials and fleet commanders for an emergency meeting.

”Their purpose is the same as the Trisolarans—to conquer Earth.”

”More precisely, they want to conquer both the Solar System and the Trisolaran civilization.”

”They refuse any negotiations. If we reject their terms, war is inevitable.”

Sai summarized bluntly.

Officials looked at each other, many still reeling from the shocking reality.

”Your thoughts?”

The young Secretary-General looked to the fleet commanders and officials.

”….”

After a moment of silence, one official finally spoke:

”Under the sophon blockade, we struggled for centuries to build our brilliant civilization. We cannot surrender just because of one outsider’s ultimatum.”

Several nodded in agreement.

”And the Starsea Empire—Empire! They’re clearly a totalitarian state. Hard to believe such a feudal system could exist in the space age.”

Another official sneered, stressing the word Empire.

In his mind, he pictured a feudal interstellar state.

Completely at odds with modern Earth.

After lengthy discussion, most still found Setsuna’s demands outrageous.

Forcing a spacefaring civilization to regress to pre-space age, submitting fully to an alien power—it ran entirely counter to humanity’s values.

”We cannot bow to tyranny.”

”If they won’t live in peace, we cannot yield so easily.”

The officials’ opinions gradually aligned.

Suddenly—

An unfamiliar transmission came through.

”I think we should accept.”

It was Zhang Beihai’s voice.

After the Natural Selection’s defection, he had cut off contact with Earth.

”Why?”

Sai asked.

”I’m considering it from the perspective of preserving human civilization.”

”I know you’re drunk on your technical achievements, but remember: in the past 200 years, under sophon blockade, the Solar System hasn’t advanced a single step in fundamental science.”

Zhang Beihai replied.

”Mongol cavalry had attack speeds comparable to 20th-century armored divisions. Northern Song’s bed crossbows had a range of 1,500 meters, similar to 20th-century sniper rifles.”

”But these were still only ancient cavalry and crossbows—they could never match modern power. Fundamental theory decides everything.”

”We cannot defeat the Trisolaran fleet, nor the Starsea Empire. Compared to the Trisolarans, their terms are actually more lenient. From the perspective of survival, we should accept.”

”Additionally, if possible, we should dispatch some fleets to escape, to preserve more seeds of humanity.”

His reasoning was clear, his tone steady.

But the space navy’s officers shook their heads.

”You’re too pessimistic. Even without that ship interfering, we could’ve dealt with the Trisolarans.”

”And look at the people—no one wants to live under totalitarian rule.”

He switched the display to Earth.

Crowds were demonstrating in the streets, waving massive banners toward the Eternal Snowfall.

”Down with the alien dictator! Humanity will triumph!”

”Have the United Fleet destroy them!!!”

”Expedition to the other world! Liberate its oppressed people! Bring freedom and democracy there!!”

The people shouted slogans with fervor, casting Earth as a beacon of liberty.

To them, their foe was merely a feudal empire.

”….”

Zhang Beihai realized persuasion was impossible. He stopped arguing, leaving the Natural Selection to continue in Proceed to Four state, putting as much distance as possible from the Solar System.

...

On the Eternal Snowfall—

The shipgirls watched in confusion.

”Wait—why do they think they’re here to give us freedom and democracy?!”

”I think my life’s pretty good—hardly suffering in misery!”

”That’s just how Trisolaris rabble are.”

Setsuna spread his hands.

Even before fighting the Trisolarans, the United Fleet had planned to grant them refuge.

Now, without even facing the Droplet, their confidence had swelled again.

Their heads were stuffed with thoughts of freedom, democracy, and equality.

He patiently gave both Earth and the Trisolaran civilization thirty minutes to decide.

The Trisolarans replied first.

A sophon connected to the Eternal Snowfall’s comms.

”Your terms are too harsh. We cannot accept reducing our species from a spacefaring civilization to caged livestock.”

”We request further negotiation.”

By Setsuna’s conditions, the Trisolarans were allowed only 50,000 survivors, living like animals on Earth for study and observation by the Starsea Empire.

The Trisolarans wanted to migrate to the Solar System, but not to live as livestock.

”I wasn’t bargaining with you.”

Setsuna raised an eyebrow.

Then—the United Fleet commander’s transmission came through.

His reply was equally unsurprising.

”Earth does not accept foreign domination.”

”We will not submit to aliens without reason.”

Shwoom—

The United Fleet shifted into combat stance.

Weapons loaded. Turrets turned.

”Oh.”

Setsuna nodded, unsurprised.

”Maybe I should’ve just let the Droplet finish you off earlier?”

”But it doesn’t matter. The result is the same.”

...

From the very start of negotiations, the Solar System Fleet’s two thousand stellar-class warships, under the space navy commander’s orders, had encircled the Eternal Snowfall in advance.

He expected at least some reaction from the enemy, but the giant ship seemed utterly unconcerned.

It simply hovered in the void, allowing the three major fleets to close in from tens of thousands of kilometers away.

Space was three-dimensional, so the United Fleet sealed every angle—above, below, and on all sides.

From afar, it looked like two thousand fireballs surrounding a single planet.

Up close, everyone marveled at the Juggernaut’s staggering size and its incomprehensibly complex structure.

Earth’s scientists could not fathom how a starship of such magnitude could have been constructed, nor how it overcame its own gravity.

”Ohhh—finally, a real interstellar war!”

”Now this is a worthy opponent for the United Fleet! That Droplet thing was nothing—fighting alien ships is real excitement!”

”What good is size? With two thousand ships firing gamma lasers or nuclear missiles, we’ll blow it to pieces, right?”

”This time it won’t be like using two thousand cannons on a mosquito, heh…”

”Make it give back the Droplet first! That was supposed to be our war prize…”

Earth’s people, watching the broadcast from Jupiter Base, remained fervently optimistic.

Some were even annoyed the Eternal Snowfall had stolen the Droplet from them, as if the Trisolaran fleet and its weapon were already the United Fleet’s property.

Meanwhile—

Ding Yi, with several assistants, departed the Quantum aboard a shuttle.

He was a scholar—there was no need for him to participate in battle.

”Run… tell them to run…”

The old man tugged urgently at a fellow officer’s arm, stumbling over his words.

”It’s fine. With a ship that size, all we have to do is disable its propulsion and weapons systems—it’ll be crippled.”

”We’ve already proven giant starships are impractical. Too big, just easy targets.”

The officer laughed and tried to reassure him.

”No… wrong. Just now, I calculated its trajectory… from when it entered the Solar System. Its speed was… it was…”

Ding Yi pointed at the holoscreen’s equations, trembling, unable to finish.

”Was what? Supersonic? The United Fleet already reaches hundreds of times that.”

The officer was puzzled.

”…Light speed.”

The next moment—

[All weapons systems online]

[Targets locked. Point-defense arrays activated]

Clack—

On the Eternal Snowfall’s massive wings, one hundred and twenty axial cannons, along with thousands of other turrets of varying size, locked onto the surrounding fleet.

Boom!

Both sides fired almost simultaneously.

The tachyon lances blazed brighter than stars—one hundred and twenty dazzling blue torrents of energy ripped through the void.

Even on Earth, the night sky lit up like day. People outdoors shielded their eyes, unable to look directly.

With speeds approaching infinity, there was no chance to react.

At the instant of firing, more than seven hundred ships directly in front of the Eternal Snowfall were completely annihilated.

The lances pierced across the Solar System into deep space, like beams of light stretching for light-years.

Boom, boom, boom—

From the flanks, the point-defense batteries unleashed torrents of fire at the upper fleet.

Designed for intercepting fighters and missiles, they tore human warships apart even more easily.

Dense energy beams and kinetic slugs shredded them into scraps, fusion engines exploding into brilliant red fireballs against the stars.

From Earth, it looked like a dazzling fireworks display in the heavens.

After suffering the first devastating volley, the United Fleet scrambled desperately to fight back.

Gamma lasers, electromagnetic rail cannons, interstellar torpedoes—every weapon the fleet had was unleashed.

The firepower, capable of scouring planetary surfaces, only raised faint ripples on the Eternal Snowfall’s energy shield.

They couldn’t even scratch the ship’s hull.

Whoosh—

When conventional weapons proved useless, several ships launched infrasound hydrogen bombs toward the bridge, hoping to kill the crew inside.

Still ineffective.

”Shields!! Energy shields!!!”

Staring at the faint blue field enveloping the Juggernaut, the Solar System Fleet realized they had made a catastrophic mistake.

This was something Earth’s imagination had dreamed of—but could never build.

Boom—Boom—Boom!!

Fireballs erupted endlessly in the night sky, shaking the hearts of people who looked up from Earth’s northern hemisphere.

Even the news anchors froze mid-broadcast.

They understood—the United Fleet was being destroyed at unimaginable speed.

And that towering ship, vast as a planet, hadn’t even fired its primary main cannon.

In just a few minutes, the fleet encircling the Eternal Snowfall was annihilated. Only debris and drifting shuttles remained.

Setsuna did not pursue the shuttle survivors. Instead, he targeted the Saturn Fleet’s command base.

Boom—

A single lance erased everything, igniting Saturn’s atmosphere in a brief flare.

”….”

”Ah…”

UN officials and Earth’s citizens fell into stunned silence.

They opened their mouths, pinched their own faces, as if trying to wake from a nightmare.

But the drifting wreckage in space, and the ever-nearing Eternal Snowfall, reminded them this was bloody reality.

The United Fleet had been obliterated—in 2 minutes and 16 seconds.

A glass of water, a trip to the restroom—and the world had turned upside down.

No back-and-forth battle, no fierce contest—only one-sided crushing.

The Eternal Snowfall accelerated, gliding into orbit above Earth.

Its shadow blanketed the entire northern hemisphere night sky, eclipsing moon and starlight beneath its colossal bulk.

Thanks to anti-gravity systems, it caused no gravitational disturbances.

Clack—

Its lower bay doors opened. Hundreds of thousands of Angeloids descended.

Their wings roared as they swept down, suppressing the last resisting ground forces.

Seeing the space fleet crushed and the Juggernaut looming overhead, Earth’s defenses lost all will to fight.

With almost no resistance, the Angeloids seized control of the world and UN headquarters.

Sai and the UN officials were brought before Setsuna.

On the Eternal Snowfall’s bridge, they trembled before the conqueror from another universe.

Around him stood shipgirls in crisp uniforms, their beauty matched by their cold, soldierly aura.

”What will become of us?”

Sai asked, secretly hoping Setsuna might show leniency for fellow humans.

”I’ll repeat my earlier question.”

”From now on, the Solar System falls under the Starsea Empire. All humans will be disarmed and return to pre-space-age life.”

”Do you accept?”

Setsuna sat casually in his chair, speaking evenly.

Then he added:

”As long as you don’t cause trouble, I don’t care what you do on Earth. Live however you want—destroy yourselves if you wish, it doesn’t matter.”

”But if you cross the line… you know the consequences.”

”!!!”

The officials fell silent with fear.

They had no doubt that if they said ”reject,” the Juggernaut’s firepower would strike Earth the next second.

Within seconds, Sai and the others nodded.

”We… accept.”

”Good.”

Setsuna felt no particular malice toward this secretary-general.

But these arrogant humans indeed needed to be broken first, before they would obey.

He stood and examined the star map, beginning to assign orders.

”Grey, take Bulin and the Angeloids, build a small research base on the Sun. We’ll use it to study the Trisolaran civilization.”

”Everyone else—scout and clear all star systems within 200 light-years. Be careful. If you encounter enemies, strike from range immediately.”

”Report any suspicious findings at once.”

”Understood.”

The shipgirls deployed, projecting hundreds of starships that streaked out in all directions.

”Clear… the star systems?”

Sai caught the unfamiliar phrase.

”Excuse me, what does that mean?”

”Exactly what it sounds like. Eliminate every alien and alien fleet within range.”

Setsuna replied calmly.

”The Empire is building a research base here. We can’t allow interference. For safety, everything within 200 light-years must be a dead zone. That way, even if enemies approach, we’ll have 200 years of warning.”

The range of a stellar base’s sensors was precisely 200 light-years. Since the Trisolarans couldn’t surpass light speed, any incoming foe would be detected centuries in advance.

More than enough.

”Ah…”

Wipe out every civilization within 200 light-years?! Humanity couldn’t even flee that far.

Sai was overwhelmed by the scale.

Then she noticed Alpha Centauri on the map.

Only 4.2 light-years away—well within range. The Trisolarans’ homeworld.

Setsuna smiled.

He lowered his gaze toward Earth, knowing sophons were still watching.

”The Trisolaran civilization will be the same.”

The Eternal Snowfall powered up once more.

Its main axis glowed faint orange.

The AI’s mechanical voice rang out:

[Fallen Star Lance on]

[Main cannon charging: 23%… 35%…]

”To annihilate a civilization is to grant it the highest respect.”

”Farewell.”

...

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