Crossover Shipgirls: Building a Dimensional Empire from Scratch

From a certain day onward, Setsuna discovered a new ”switch.”

He realized a way to resolve minor disputes between shipgirls. Even someone as aloof as Richelieu or as possessive as Taihou could grow harmonious after engaging in some deep conversation.

Initially, the two were a bit shy about it. However, as time passed, their relationship became increasingly amicable. They could now naturally extend invitations to each other, leaving other shipgirls utterly dumbfounded.

Aside from the occasional disagreement over work matters, their daily interactions had become extraordinarily peaceful.

”Is this… team building?”

Setsuna felt that this discovery held significant ”guiding significance” for maintaining harmony among his wives in the future.

However, upon further thought, while a two-person ”team-building activity” posed no issues, three or more…

Well, focusing on improving physical fitness seemed crucial.

...

Meanwhile, over 10,000 Bulins brought from the capital temporarily took up residence in the Azur Lane world.

Piloting their respective vessels, they began constructing various resource extraction facilities across the seas. Alongside them were submarine shipgirls from all factions. Equipped with tools and scanning devices, these small yet capable shipgirls roamed the depths of the ocean, marking countless resource sites.

Coal, iron, rare earths, oil… Although deep-sea resource extraction posed significant challenges, it was no problem for Bulins and shipgirls.

The Azur Lane world quickly became a hive of activity. The seas were dotted with Bulin construction crews, and it wasn’t unusual to see submarines dressed in breezy outfits zipping across the surface on their vessels.

...

”Commander, according to estimates, this planet’s extractable resources amount to approximately 2–3 times that of Earth…”

”In terms of mineral content, there’s slightly less ore. However, the deep-sea regions hold astonishingly abundant oil reserves, far beyond what we initially anticipated.”

After several days of surveying, Richelieu presented a detailed report to Setsuna.

”Oh, so you guys are pretty loaded, huh? So, the reason the port lacked resources before was because you were stuck at home, blockaded by the Sirens?”

Setsuna skimmed through the report. While this planet was somewhat smaller than Earth, its resource reserves were incredibly rich.

Moreover, extraction was straightforward. Both Sirens and shipgirls were already highly familiar with the area.

As long as there were enough Bulins, once basic infrastructure construction was completed, the planet could quickly begin providing resources back to Earth.

”Should we consider initiating space exploration on this side?” Richelieu asked again.

”For instance, launching satellites or investigating other habitable planets in the star system?”

”Not for now. Focus on deep-sea resource development.”

Setsuna pondered for a moment.

Simultaneously pursuing space development in two worlds would be far too costly. Furthermore, based on information from the Sirens and his own understanding, engaging in aerospace projects in the Azur Lane world carried significant risks.

Better to stick with extracting resources and strengthening the port’s infrastructure.

If the Sirens want to blockade, fine—they’re tough. But he had another world to roam the stars in. Returning here occasionally to bring the shipgirls on vacation was enough.

...

A few days later, Setsuna was lounging in the port, flanked by Taihou and Richelieu, engaged in lighthearted banter.

Suddenly, he received a communication request.

”Hm? A message from Chaldea?”

Setsuna casually opened the holographic interface, establishing a connection. On the other side were the familiar faces of Dr. Roman and Leonardo da Vinci.

”Hello, Mr. Setsuna, long time no see!”

”How have you been? How’s that world treating you?”

Da Vinci waved cheerfully in greeting but froze upon getting a clearer look at the scene.

Setsuna was lounging comfortably on a sofa. On his left was a glamorous young woman with twin tails and a strikingly seductive charm. On his right was a dignified blonde with red eyes, her refined and aristocratic aura unmistakable.

Standing just behind him was a silver-haired maid, impeccably elegant, holding a fruit tray. With a graceful bow, Belfast offered, ”Commander, would you like some fruit?”

”I’ll handle it,” Taihou said, reaching out to pick a glistening grape and gently feeding it to Setsuna.

The scene resembled a royal court, but no emperor in history had ever been surrounded by consorts of such caliber.

”???”

Da Vinci blinked several times, sensing a major discrepancy in her understanding of Setsuna.

The last time they spoke, Setsuna had mentioned his Earth was in ruins, much like Chaldea’s, and that he was working on rebuilding civilization.

But now… this was a starkly different picture!

”Hello, hello, I’ve been doing great,” Setsuna greeted Da Vinci politely.

”…”

”Yes, I can see that,” the dark-haired genius replied, her voice laden with deadpan disbelief.

”Where’s Ritsuka Fujimaru?” Dr. Roman chimed in, concern evident in his tone.

His attention was on Chaldea’s Master. While Gudako’s unorthodox approach of ”Offline Master System” had made waves, she was still their comrade. Roman, in his paternal way, always kept tabs on her well-being.

”She’s probably studying magic with Lucoa right now,” Setsuna mused after a moment of thought.

Gudako had only visited the Azur Lane world briefly to explore its wonders before promptly returning to the capital via the dimensional anchor.

”Lucoa? Who’s that?”

Neither of the Chaldeans recognized the name.

”A very powerful… magician. Her mastery of magic likely surpasses that of any mage from the Age of Gods,” Setsuna replied succinctly.

The Feathered Serpent God was leagues beyond any human mage. She was arguably the strongest individual under Setsuna’s command.

”Ohhh…”

Roman and Da Vinci nodded in understanding.

They didn’t know Lucoa but trusted Setsuna’s judgment. If he said she was exceptional, it was no exaggeration.

”With such an extraordinary teacher, Ritsuka Fujimaru must be well on her way to becoming a remarkable magician and Master. I imagine she’s already mastered many magical techniques we’ve never even dreamed of,” Roman said, beaming with fatherly pride.

Da Vinci, equally moved, added, ”She made the right choice in following you to another world. It’s practically like studying abroad. When she returns as a full-fledged magus to rebuild Chaldea, it’ll be a story for the ages.”

”…”

Setsuna remained silent for a moment, suppressing a sigh.

He couldn’t bear to tell them that Gudako was, in fact, closer to becoming a cybernetic Berserker—piloting a Gundam and charging into battle with a hammer-spear—than a proper mage.

Yes, she had learned some magic, but only to reinforce her Gundam.

”So, what’s the situation? Did Chaldea pinpoint a Singularity?”

Setsuna asked.

”Yes, we’ve located the second Singularity, set in the 1st-century Roman Empire,”

Dr. Roman replied, his tone apologetic.

”The exact details of the Holy Grail and the disruption it’s caused are still unclear. I’m sorry; our observation precision is still somewhat unstable.”

”So, if you’re available, could you help us address the issue there?”

”…”

Setsuna sat up and contemplated briefly.

It didn’t matter whether Roman understood the full details of the Singularity; Setsuna did.

The second Singularity—The Eternal Madness Empire.

He was intimately familiar with its characters and plot and could clear it quickly.

However, given his presence, the original story was bound to go off the rails.

”Commander, are you planning to go personally?”

”If it’s not too difficult, maybe Ritsuka Fujimaru can handle it. You could send a few Heroic Spirits or even some Sirens to back her up, right?”

Taihou pouted, her arms draped around Setsuna’s neck.

”Uh… theoretically, the boss of the second Singularity wouldn’t stand a chance against a combined assault from Sirens and Heroic Spirits.”

Setsuna mulled it over.

”But I still need to go personally.”

”Huh? Why?”

Taihou clung to him, sulking like a petulant girlfriend.

”In that case, I want to go with the Commander.”

”I need to summon some Heroic Spirits, and this Singularity has a Demon God Pillar.”

Setsuna explained.

During the previous Singularity, the Dragon Witch incident, he had used a fake Holy Relic given by Ning Hai to summon Artoria.

However, after returning, he discovered that summoning Heroic Spirits was impossible on Earth—there was no Root or Throne of Heroes in this world.

To summon more Heroic Spirits, he had to revisit the Type-Moon universe and bring them back.

At present, his Heroic Spirits included Jeanne Alter, Jeanne d’Arc, Artoria, and Mash.

It was time to try his luck and see if he could expand his roster.

Additionally, according to the original story, this Singularity featured Lev Lainur Flauros, the mastermind behind Chaldea’s bombing, as well as a Demon God Pillar.

Both were worth investigating.

”Hmm… alright, I’ll handle the preparations. I’m coming with you,”

Taihou declared resolutely.

”Not so fast, my dear flagship! Give the rest of us a chance, will you?!”

Formidable pulled Richelieu back, wearing an expression that seemed to say, ”If you and Taihou both go, then the rest of us will be left with nothing to do but watch your performance.”

”You stay in the capital. Those few Siren girls just arrived, and there’s plenty they’ll need your help with,” Lu Chen said, gently tapping Richelieu’s forehead.

”Besides, there are also some matters with Akashi that need attention.”

”Don’t worry, with our combat strength, clearing this singularity won’t take long.”

”Well… fine. Good luck, then. I’ll be waiting for you back home,”

Richelieu replied, giving Setsuna a quick kiss on the cheek before stepping aside.

”Ahem—prepare for departure,”

Setsuna cleared his throat, rallying his group.

”This time, we’re heading to the Roman Empire to restore order to Rome!”

”Bah! We’ve already established Constantinople as our capital. We are Rome—this is about eliminating imposters!”

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