Crossover Shipgirls: Building a Dimensional Empire from Scratch

Aside from MANTIS technology, Grey showed Setsuna several other technologies left behind from the Previous Era.

”The Divine Keys” and the ”Key of Blankness.”

”To fight against Herrschers, Dr. Mei decided to use Honkai power to counter Honkai. She used Herrscher cores as energy drivers to forge a special weapon—the Divine Key.”

”The Divine Keys can manifest effects based on Herrscher authority. For example, Fu Hua’s Fenghuang Down can manipulate brain signals, while the Void Archives can analyze weapons and tools, and so on.”

Grey explained through the holographic interface.

”Although I think turning Herrscher cores into weapons is somewhat wasteful, given the circumstances of the Previous Era, they probably couldn’t think of a better solution.”

Setsuna nodded in understanding.

At that time, not to mention in-depth research of Herrscher cores—even if the Divine Keys had appeared any later, humanity would’ve been forced into rout by the Herrschers.

Senti, upon hearing about Herrscher cores being turned into weapons, gave a strange look and clicked her tongue:

”Humanity borrowing Herrscher power to make weapons—how could that ever compare to a true Herrscher?”

”Mhm, I also think the Divine Keys don’t utilize Herrscher cores efficiently. The real valuable thing is the ’Key of Blankness.’”

The nanobot projected a somewhat peculiar-looking set of armor.

”Dr. Mei spent immense effort studying Imaginary Space and Honkai energy, and she proposed an interesting law:”

”Herrschers’ Honkai energy exists in Imaginary Space, and the Herrscher core is the key to open Imaginary Space.”

”Based on this theory, she created the Key of Blankness.”

”That’s a set of armor that can embed a Herrscher core. It allows the Herrscher core to connect with the human body, letting humans briefly link to Imaginary Space—becoming Herrschers themselves.”

Simply put, the Key of Blankness uses Herrscher cores as keys, enabling its wearer to connect to Imaginary Space for a short time.

Thus, they could draw upon Honkai energy within Imaginary Space, gaining power rivaling a Herrscher.

While speaking, the nanobot added:

”In my view, in actual combat, the Key of Blankness far surpasses most Divine Keys. If not for Dr. Mei’s body being unable to withstand it, it could have achieved even greater effects.”

Depending on which Herrscher core it carried, the Key of Blankness could manifest different abilities.

Dr. Mei had once used the cores of the Herrscher of Thunder and the Herrscher of Wind to face the Herrscher of Dominance.

Unfortunately, that experiment caused irreversible damage to her body. For the sake of her life, the project was temporarily suspended.

The technical data on the Key of Blankness had also been copied into Griseo’s Ark.

”So? You plan to make a Key of Blankness?”

Fu Hua asked.

”In the last era, I knew Dr. Mei had used it… Honestly, I don’t think you people really need it?”

She glanced around at Setsuna and his companions.

They were either shipgirls, dragon girls, or Spirits.

Given their abilities, the Key of Blankness’ power boost seemed somewhat redundant.

”No, no, no. The Key of Blankness has two derivative technologies. We can study it further.”

Grey raised two fingers.

”First, the Key of Blankness can be modified into single-soldier combat armor—equipped with a power furnace, nano-composite armor, and tactical modules. Combined with MANTIS tech, it can unleash immense power.”

”That’s called Valkyrie Battlesuit.”

Setsuna reminded Grey with a laugh.

Sure enough, researchers tended to think alike. Otto had dug into the Key of Blankness to make Valkyrie Battlesuits for Schicksal troops.

The nanobot, upon seeing the design, had come to the same conclusion.

”Later, I’ll give you a Shadow Knight, though I still prefer Dea Anchora.”

He patted Fu Hua on the shoulder.

”???”

Fu Hua was baffled.

”The second way… I’m very interested in the Key of Blankness’ ability to use Herrscher cores…”

Setsuna rubbed his chin as he spoke.

”In theory, the Key of Blankness can embed multiple Herrscher cores, granting the wielder multiple Herrscher powers. Unfortunately, due to experimental limits and her own physical condition, Dr. Mei never managed to study it further.”

”Using the Key of Blankness also places a heavy burden on the user’s body, making it impossible to unleash one hundred percent of a Herrscher’s power…”

As she spoke, Grey fixed her gaze on Setsuna:

”Conveniently, we have someone here who theoretically is compatible with every power system in the world, whose physical fitness is off the charts—a man who can take a subspace light spear to the face and chew hydrogen bombs like candy.”

”Huh? The Commander?”

The shipgirls and dragon girls froze for a moment.

”You want to use the Key of Blankness to build armor for the Commander?”

Though Herrscher powers were impressive, everyone still felt Valkyrie Battlesuit’s style didn’t really suit Setsuna.

”What are you thinking?! I said study the use of Herrscher power, not make bikini armor for the Commander to wear!”

The nanobot knocked on the table.

”We can try applying the Key of Blankness technology by embedding Herrscher cores into the Eternal Snowfall. That way, he gains the ability to use Honkai energy and Herrscher authority.”

”Anyway, the starship and Commander are one and the same. His body’s durability and adaptability should allow for perfect compatibility.”

”In the future, once the Commander’s fitted with ten or so cores, tsk tsk… I think even without the starship, you could crush the Final Herrscher with your bare hands.”

”Adding a whole new power system, huh…”

Setsuna thought it over.

Whether it was MANTIS tech, the Divine Keys, or Valkyrie Battlesuit, they didn’t mean much to him—they were better suited for his companions.

But Herrscher authority? That was truly appealing.

”Approved. Begin research and modifications here as soon as possible.”

...

Ka—

The Eternal Snowfall hovered near the space station.

Considering that Honkai was this world’s unique trait, it was only natural to conduct modifications here in the Honkai world.

Transferred from the base, the Honkai-research lolis and Bulins began drafting a detailed modification plan.

Applying the Key of Blankness technology to the Eternal Snowfall didn’t require any massive changes to weapons, engines, or structure.

Since the starship and Setsuna were of one mind and body, all they needed was a place to install the Herrscher core.

The process wasn’t complicated.

During testing, Setsuna’s adaptability to Honkai energy far surpassed Fu Hua and Griseo’s, on par with the Herrscher of Sentience.

His physical endurance was also more than enough to withstand any side effects of the Key of Blankness.

And with Dr. Mei’s detailed records at hand—

Within just three days, the research lolis produced a full design plan.

Equipped with special-type Bulins wielding their rainbow hammers, they began working in the Eternal Snowfall’s main control chamber.

Watching them disassemble and reassemble the starship’s control console and its precision components at visible speed, Fu Hua and Griseo were astonished.

”They only glanced at the design once, right?! Can they really understand everything inside? And why are they all using hammers for construction?!”

The two voiced the exact same question.

”This is the Empire’s cornerstone. Don’t worry about the details. If they say it works, then it works.”

”Just wait for good news.”

”...”

...

On the space station.

Aside from the research lolis’ modules for observing Earth, simulating historical development, and conducting experiments—

There was also an enormous activity ground.

From the side extended a boundless platform, its surface made of bluish-gray composite metal. The material was tough enough to withstand direct bombardment from small starships.

Looking up, one could see the endless starry sky.

An invisible energy shield separated cosmic radiation and the vacuum of space, while gravity generators here simulated Earth’s standard 1G gravity.

At this moment, Fu Hua, clad in her Azure Empyrea form, stood at one end of the plaza, holding the Xuanyuan Sword in one hand, staring across at Setsuna.

During the modification of the starship, apart from raising Griseo, Yae Sakura, and Yae Rin, Setsuna would spend his free time sparring.

Just to get a little advance practice with Honkai energy.

”Come, I won’t use ship rigging or Gundams. Just my first form, to play with you.”

He drew a longsword decorated with golden patterns, ornate and magnificent—the Sword in the Stone.

Beside them stood Senti, Griseo, the Yae sisters, and Kallen, watching the show.

They had seen shipgirls and dragon girls fight, but as for Setsuna himself, beyond knowing he commanded a Juggernaut that blotted out the sky, they didn’t know much.

Shwoosh—

Fu Hua’s figure vanished instantly. With a shrill tearing sound, she flashed forward, sword light striking straight at him.

Her movements were so fast that Kallen couldn’t even catch her afterimages, and even Griseo, a fellow fusion warrior, couldn’t follow the immortal’s speed.

Yet in Setsuna’s eyes, it was no different from slow motion.

Clang!

He swung casually, the Sword in the Stone knocking aside the supposedly inescapable strike.

Fu Hua pressed on, mixing sword strikes with punches and kicks.

Each blow carried crushing power, yet Setsuna deflected them all with ease.

Every clash of blades shook the entire platform with violent shockwaves.

”Ki · Impact!”

Smack!!—

Setsuna firmly caught Fu Hua’s punch, his feet unmoving.

With a tug, the immortal fell straight into his arms.

Unfortunately, because of their size difference, there was no softness to be felt—just a bit uncomfortable and awkward.

”Good reactions, but you don’t actually know how to wield a sword.”

Fu Hua glared at him, leaping back a few steps.

His moves weren’t anything special, no techniques or forms. Purely by swordsmanship, he was no match for a true Shenzhou swordsman.

He simply relied on overwhelming speed and power, seizing absolute advantage in every clash.

His speed outstripped everyone else—blocking before they could even strike. His strength dwarfed everyone else’s—making brute force breaks impossible.

If a sword master were dragged here to fight him, it would just be a flashy performance before being beaten to death with basic attacks.

”I’ll repeat myself—unless your attack speed surpasses lightspeed, don’t think about getting the first move on me.”

Setsuna smiled.

”As for strength… humans can’t compare with a nuclear reactor, right?”

”...”

Fu Hua fell silent for a moment, then let out a sharp cry and attacked again.

The surrounding environment suddenly changed dramatically.

The dark sky blazed with fiery clouds, light burning across half the heavens.

Vast Honkai energy condensed, warped, and shifted at Fu Hua’s will—

Finally forming a colossal unsheathed sword, descending from above.

”Immortal, isn’t this the move you used against Sirin?!”

Setsuna looked up, half the sky dyed orange-red.

”I know your body is absurdly strong, but how about your will and spirit?”

From above, Fu Hua looked down at him.

”Don’t worry. If you can’t handle it, I’ll stop.”

This was her unique ultimate technique: the Taixuan Eminence.

The extremity of transformation. Even without a sword, there is sword. Through spirit, the sword is formed, sword qi manifests. It is the resonance of divinity.

The extremity of change, the wondrous expression of all things, beyond what form can constrain.

Without shape, yet no shape is needed. The sword fills the space—the sword is space itself. Thus it is everywhere, unstoppable.

The Taixuan Eminence simultaneously targeted both spirit and body. There was no escape, no evasion.

The world-shaking strike descended with a roar.

”Eh? This old relic is really that strong?!”

Senti shivered as she watched. She herself couldn’t use this move, and in some ways, the Taixuan Eminence was like a Herrscher-killer.

She recalled how she had often teased Fu Hua before—only thanks to the immortal’s magnanimity had she not been held accountable.

”Impressive effects, but not enough. Too slow.”

Setsuna raised the Sword in the Stone skyward.

BOOM!!!!

A torrent of blue magical energy erupted upward like a pillar of light, scattering the colossal conjured divine sword.

The Honkai energy condensed in the air instantly collapsed.

Fu Hua had planned to resist, but even the residual energy carried an incomprehensible, irresistible power.

Even in human form, their output levels weren’t remotely on the same plane.

Thud—

Setsuna easily caught the falling Fu Hua.

”You…”

The immortal looked at him with a complicated expression.

”Your spirit wasn’t affected at all?”

She had assumed his physical defense was due to an extraordinary body, winning by brute magical output in a direct clash.

But to resist mental attacks as well—that was difficult to believe.

”Nope. Do you know what it means to launch a mental attack against me?”

Setsuna chuckled, pinching her cheek.

”It’s the same as attacking the Eternal Snowfall’s main control system. What you face is the firewall of a Juggernaut-class supercomputer reinforced by sophon processing.”

”...”

”Shameless.”

Before Fu Hua could reply, Senti spoke up first, spitting the word.

With man-ship unity, he could call upon the starship’s processing power to resist psychic attacks.

What normal person could match a supercomputer and sophons in sheer calculation power?!

No wonder every time she’d tried secretly nudging Setsuna’s consciousness, she had failed—only to get a knock on the head instead.

”...”

Fu Hua gazed at him for a long moment before speaking solemnly:

”Your strength is immense, but your use of it is too crude and wasteful. If you could refine it further…”

”With your power, if you could master the Taixuan Eminence, there would be no one in the world who could withstand even a single strike.”

”Hmm…”

Setsuna thought for a moment.

Truthfully, with the Fallen Star Lance, none could last more than two moves against him anyway.

But it wouldn’t hurt to pick up another skill. The Taixuan Eminence was useful in human form—he couldn’t always use a planet-buster cannon to swat mosquitoes.

”Then I’ll trouble you, Immortal, to teach me when you have time.”

”I’ve already received your favor, removing the side effects of Blade Mantra. It’s only right I repay you.”

Fu Hua was about to say more when—

”Oi, are you two done hugging? What is this, Gone with the Wind?!”

Grey’s voice suddenly cut in.

She peered at Setsuna and Fu Hua through the holographic interface, thinking they were up to something indecent in public.

”We were sparring in swordsmanship.”

Fu Hua’s cheeks flushed as she scolded, rising to straighten her robes.

”Sparring? More like one day you’ll ’spar’ your way onto a bed!”

”What’s so fun about primitive weapons anyway? Want me to send you a dozen antimatter grenades? Much easier to use.”

The nanobot dismissed such mystical nonsense, then cleared its throat.

”Commander, the Eternal Snowfall’s Herrscher Core drive module is complete.”

—

—

40 Advanced Chapters Available on Patreon:

Patreon.com/DaoOfHeaven