Crossover Shipgirls: Building a Dimensional Empire from Scratch

”Uh...”

After witnessing the great purge of the Mage’s Association nobility, the atmosphere within Chaldea became rather strange.

They realized that as Human History was reconstructed, the entire social order of Earth had undergone earthshaking changes as well.

”Ahem, don’t worry. Just continue observing the world the same way as before.”

Gudako said.

”Anyway, those guys from the Mage’s Association never did much proper work besides causing trouble for us...”

”Instead of letting them drag us down from behind, it’s better to solve everything once and for all, right?”

”Uh...”

Roman felt that Gudako was becoming more and more like Setsuna.

”So what about things here from now on?”

”Business as usual.”

Setsuna thought for a moment.

”Under the management of the Starsea Empire, most people’s lives won’t be any different from before. The overall social order won’t change much either.”

”The Mage’s Association and the Holy Church are exceptions. All remaining magi must be brought entirely under our jurisdiction.”

Even the goddesses of the Heaven obediently followed the rules of the Starsea Empire, and those overwhelmingly powerful Cthulhu girls were quite orderly as well.

For that group of magi to try acting like outlaws was nothing but wishful thinking. Getting crushed by an iron fist was only natural.

”Then Chaldea will continue its ongoing observation of Human History and Earth. Contact us if anything comes up later.”

”Mm... Without the Mage’s Association, there shouldn’t be too many messy incidents, right?”

...

Members of the Magic Division dispatched from the capital began fully taking over the world’s entire mystical system.

Sophon handled routine administrative affairs, while professionals were responsible for matters on the magic side.

Click—

Several small spacecraft, carrying Mio, Tohru, and members of the Magic Division, landed respectively in the Atlas Mountains of Egypt and near the North Atlantic.

The Mage’s Association had three primary departments.

The Clock Tower, the Atlas Institute, and the Wandering Sea.

The Clock Tower headquarters had suffered devastating damage in the battle. Most nobles and prestigious families had been reduced to ashes in Tohru’s dragonfire, leaving only basic cleanup work.

The Wandering Sea and the Atlas Institute were preserved relatively intact.

They were located in remote areas far from human society, hidden within magical barriers and normally closed to the outside world.

The Atlas Institute was even known as a ”living hell where not even light could escape,” specializing in alchemy and advocating an even more extreme secrecy policy than the Clock Tower.

Of course, the now-subjugated magi were already standing in neat rows several kilometers away, trembling as they awaited the Imperial Magic Division’s takeover.

Terrified that another round of nine-clan extermination might come their way.

”Greetings. I am Zepia Eltnam Atlasia, Director of the Atlas Institute. All instructors and Lords of the Institute are present and await your orders.”

A middle-aged man in mage robes bowed humbly to the group, with other members of the Atlas Institute standing behind him.

”Mm, very good.”

”We will first conduct a full inventory of all personnel, equipment, and research achievements of the Institute. Please cooperate with our work.”

”This mage academy will also be reorganized and exist as a secondary research base within the Type-Moon world.”

The first to step down was a beautiful silver-haired girl—the Spirit of Origin.

The accompanying personnel included Tohru, Elma, several small girls responsible for magical research, and a group of Crimson Demon lolis studying at the Magic Academy.

They had been studying at the Magic Academy for quite some time. Rarely having the opportunity to go out and encounter magical systems from other worlds, they were practically bursting with excitement.

”Ohohohoho—”

”My name is Megumin! I am the number one mage of the Crimson Demon Clan and wielder of Explosion! Offer up all your knowledge to me!”

Megumin struck what she believed to be an incredibly cool pose, drawing sideways glances from the magi, who wanted to complain but did not dare.

Thump—

Yunyun knocked her lightly on the head.

”Watch your image!”

”Ahem...”

”You all, go sort through the Atlas Institute’s documents and materials. Categorize them and hand them over to the Research Institute.”

Mio efficiently assigned tasks.

”Any valuable magecraft and materials will be taken back to the Magic Academy for study. The rest will be handed to Lucoa for storage in the Imperial Grand Library.”

”Yes—”

The little girls responded and began flipping through and searching the magic academy, which was likewise located underground and buried deep beneath the mountain range.

The magi were astonished to discover that in terms of magical attainment, these seemingly young girls far surpassed them.

The Magic Academy’s curriculum drew from countless worlds. The breadth and depth of its knowledge were far beyond what ordinary magi could compare to.

Although the Crimson Demon lolis were all somewhat airheaded, after education at the Magic Academy and under Mio’s guidance, their magical level even exceeded that of the various family Lords.

The Atlas Institute’s scale and magical attainments could not compare to the Clock Tower. Most Type-Moon magecraft did not catch the Magic Academy’s interest.

However, the Atlas Institute specialized in alchemy, while the Wandering Sea focused on ancient magecraft long lost to time.

From these two academies, they still managed to find some valuable items.

A few days later.

When the reconstruction work at Chaldea was largely complete, Mio and Tohru reported the preliminary inventory results to Setsuna.

They brought along a purple-haired little girl with a ponytail to stand before him.

”My husband, the magic of this world—or what they call magecraft—has theoretical structures similar to the magic we previously mastered.”

”Under normal circumstances, casting magecraft relies on magic circuits and mystic codes. It does not have large-scale promotional value and can only be used as an elective course...”

Given the Starsea Empire’s technological level, producing artificial magic circuits and mystic codes was not difficult, but there was no real necessity.

The materials brought back from Konosuba, Re:Zero, Overlord, and even the Dragon Maid world were more than enough for the magic lolis to cultivate. In terms of power and portability, there were also magic scrolls available in massive quantities.

”But we found these.”

Tohru directed several Angeloids to carry over a pile of ancient books. Gudako casually flipped through them, only to find incomprehensible scribbles.

That conservative group of magi obviously did not possess advanced things like digitalized office systems.

”One thing at a time. This is Sion Eltnam Sokaris, a genius alchemist of the Atlas Institute and the Director’s adopted daughter.”

”We intend to have her join the Magic Division.”

The dragon girl gently patted Sion’s back, signaling her to step forward.

”Mm... She has exceptional attainments in alchemy and magecraft. Chaldea’s spiritron calculation device and the imaginary number observation machine, were both built by her.”

”Its full name is the Spiritron Calculator Trismegistus,” the purple-haired girl corrected.

”Oh?”

Setsuna sized up the somewhat nervous little girl.

She wore the ceremonial uniform of the Atlas Institute and a white miniskirt, along with a purple cylindrical hat. Her long purple hair was braided into a lengthy plait, and her features still carried a hint of youthful immaturity.

Everyone was already familiar with the spiritron calculation device. It was used to project people to singularities at various points in time.

From the first time he saw that device at Chaldea, Setsuna had realized its enormous value. He had persuaded Roman at length to hand over the remaining data, spending considerable resources to recreate it.

Afterward, in operations across multiple worlds such as Date A Live and Heaven’s Lost Property, spiritron transfer technology had proven immensely helpful.

Now, the very creator of the spiritron calculation device stood before him. She fully deserved the title of genius.

”Explain your research to the Commander again,” Tohru gently urged her.

”Mm...”

”Previously, I was observing imaginary number space. Theoretically speaking, after leaving real number space, one can reach another world through imaginary number submergence. I also wanted to attempt building an imaginary number submarine, but the Atlas Institute’s research has now been suspended...”

Sion immersed herself in her theories, rambling on at length like any scholar intoxicated with research.

”???”

”What? Imaginary number submarine? Imaginary number observation machine? What are those?”

Gudako was completely baffled.

”...”

Setsuna pondered for a moment, recalling several key terms from distant memories.

”...That thing is used to go to Lostbelts.”

”Very good. You’re hired. Build whatever you want. Go—take her to meet the invincible Bulins.”

...

After settling Sion.

Mio reported another matter to Setsuna.

”Within this world’s magical system, what interests us most are the Five True Magics that have been passed down, as well as the research concerning the Root.”

”Judging from the records regarding the Five True Magics... mm, they can indeed be called true magic. Unfortunately, the documentation is far too scarce.”

In the Type-Moon world, true magic was something more powerful and more mysterious than magecraft.

Any ability that could be replicated through technology or achieved by similar means could only be called magecraft.

As human civilization continued to advance, more and more things became achievable through science, and most forms of true magic gradually degraded into magecraft.

Only the Five True Magics remained.

The First and the Fourth had too few surviving records. Their details were unknown.

The Second Magic granted the ability to freely traverse parallel worlds and draw nearly infinite energy from them.

The Third Magic, the Heaven’s Feel, materialized the soul—achieving complete immortality. Upon its completion, the soul would become a perpetual motion engine, providing an endless source of magical energy.

This Magic had been inherited by the Einzbern family. The Holy Grail War system itself had been constructed for the sake of realizing the Third Magic.

The Fifth Magic was likewise hereditary, similar in nature to time travel.

”All Five True Magics are related to the Root. Whether organizing Holy Grail Wars or pursuing alchemy and Age of Gods magecraft through various methods, the magi of the Mage’s Association have devoted their entire lives to one single goal: reaching the Root.”

”Mm... I believe this should also be the key focus of our research into the Type-Moon world’s magical system?”

Mio tilted her head.

The Root was the origin of all phenomena—the cause of everything. Anyone who could draw power from it possessed unimaginable abilities.

”The Five True Magics and the Root...”

Setsuna thought for a moment.

”For us, those are probably the only things here with real value.”

”Do you have an entry point? Use Sophon for a comprehensive global search, or rely on spiritron transfer?”

The magi of the Mage’s Association had explored the Five True Magics and the Root for countless years. Very few achieved success. Quite a few met disastrous ends instead.

The Starsea Empire had far more methods at its disposal. Whether deploying Sophon for a world-scale search or traversing time directly, both were possible.

”Uh... no.”

Mio shook her head.

”Before coming to this world, I read a great deal of information about the Type-Moon setting.”

”The easiest way to research the Five True Magics and the Root is to find people—those connected to them. Once we locate them, every difficulty can be resolved.”

”Anyone linked to the Root is bound to be an extraordinary magus or possess abilities far beyond ordinary humans. If they join the Magic Division, we can grasp the entire magical system of this world.”

”Additionally, the Type-Moon world appears to branch into countless parallel timelines. We need to explore them as well.”

As she spoke, Mio revealed a sly smile. Puffing out her cheeks, she leaned closer as if acting spoiled, gazing up at him.

”Mm... I suppose this is also the Commander’s favorite approach? You enjoy bringing girls back from different worlds, don’t you?”

”?”

Setsuna froze for a few seconds.

”People connected to the Root in the Type-Moon world?... I can think of one—no, two. They’re both quite formidable.”

”You’re planning to explore the other worlds here as well?”

”Yes.”

The members of the Magic Division nodded in unison.

”Since the Second Magic allows free travel between parallel worlds, that proves this world isn’t singular. With the aid of the spiritron transfer device, we can appear at any point in time in any given world. It’s very convenient.”

”We plan to use Chaldea as a pivot. After fully absorbing the Mage’s Association’s achievements, we will expand research here into parallel worlds, Lostbelts, and the Root.”

Chaldea was now essentially Gudako and Setsuna’s backyard. It could not be more suitable as a base for exploring the Type-Moon universe.

”...Are you planning to fast-forward straight into Tsukihime, Witch on the Holy Night, and Kara no Kyoukai? Is Magical Girl Illya next too?!...”

Setsuna felt that the Magic Division was frighteningly efficient.

”Approved.”

”Come to think of it, among the four main heroines of Type-Moon, we only have one here so far. Mm. Keep up the good work.”

...

A few days later.

Aside from a portion of Angeloids stationed at Chaldea and members of the Magic Division handling the remaining affairs of the Mage’s Association,

The expedition team boarded the returning starship.

Rumble—

The starship pierced through the clouds and descended into the base outside the capital.

This had originally been the decisive battle to defeat Goetia and restore Human History.

Handling the Mage’s Association and taking over the world had taken a bit longer than planned, but overall, the harvest was still plentiful.

”Mm... We brought back a bunch of ahoges, and a whole squad of strange Heroic Spirit counterparts.”

A small team of ahoge Kings—including Saber Alter, Saber Lily, Caster Saber, Lancer Alter, and others—followed behind Setsuna, forming quite the spectacular sight.

Stheno and Euryale happily welcomed yet another little sister Medusa. At this point, Medusa possessed three forms—from Ana to Gorgon—small, medium, and large models.

The three of them looked at one another and felt that the Starsea Empire was truly incredible.

Not only had it fulfilled the dream of the three sisters’ reunion, it had even added two extra members.

The Magic Division collected all materials from the Clock Tower, the Wandering Sea, and the Atlas Institute, reorganizing them into a new research group dedicated to studying the Type-Moon magical system.

They would begin research and exploration into the Five True Magics, the Root, and parallel worlds.

As for Gudako, not only had she completed her mission, but a number of delightful things had also happened, leaving her in an exceptionally good mood.

”Commander, come stargazing with me tonight~”

The girl frequently looked at him with a gaze so sweet it was almost cloying. Even the shipgirls stationed at the base got goosebumps just watching from afar.

”Also, my cat can do backflips. Want to come see too?”

”???”

”You... and the Commander?”

Belfast asked tentatively.

”Yes!”

Gudako replied righteously.

”From now on, we’re sisters on the same pole! Ah, please take care of me!”

”Tonight, Ritsuka Fujimaru joins the hunt—oh no, Ritsuka Fujimaru joins the party!”

”What?!”

Belfast was horrified. The teacup in her hand clattered to the floor. She had never heard such a blunt and bizarre declaration.

”...”

Setsuna realized that this girl constantly switched between embodiment of Humanity’s Evil and pure, adorable, responsible ordinary girl. His head began to ache.

”Tch. I had the Commander stripped of armor and begging for mercy last time. Completely unable to rise again.”

Gudako immediately began bragging the moment she realized everyone present was on their side.

Tap—

Setsuna flicked her forehead.

”Oh? You said that yourself. Tonight, you’ll receive special attention at the party.”

—

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