Crossover Shipgirls: Building a Dimensional Empire from Scratch

The Rasiel not only allows for reading the past but also enables interference with the future. However, the difficulty and energy consumption required for such interference far exceed those needed for simply retrieving information.

The larger the scope and intensity of the interference with the future, the greater the consumption. For example, making an ordinary person accidentally spill coffee on their clothes during breakfast the next day is a simple task that requires just a few strokes to record.

But writing something like ”Humanity will build a faster-than-light spaceship in 20 days” or ”The sun will explode in 1 hour” is completely impossible to achieve. The book cannot interfere with affairs beyond Earth, nor can it create things out of thin air.

”I’m so weak?!”

Nia Honjo plopped onto the sofa, feeling like she had been scammed.

”Wait, let me try with you.”

Setsuna suddenly became interested.

Nia was a native of this world and had only just become a Spirit, with relatively weak spiritual energy. It made sense that she couldn’t extend the influence of Rasiel beyond Earth. However, Setsuna, having traversed multiple worlds and possessing a strong compatibility with different power systems, might be able to expand its capabilities.

”I’ll transmit some additional energy to you. Try using it to search in Rasiel.”

Setsuna grasped Nia’s hand.

”Ah...”

The experienced otaku girl let out an involuntary murmur upon her first close contact with a man.

To be fair, Nia did look quite alluring in her nun outfit.

Then, she felt a unique energy flowing from Setsuna’s hand.

”What is this? It’s different from spiritual energy?”

”Probably a mix of Wisdom Cubes, mana, and other things,” Setsuna replied. As he accumulated more power systems, although his primary source remained the Wisdom Cubes, he could simulate and merge them into different forms of energy.

”Ohhhhh—”

Nia felt an unprecedented surge of magical energy within her body.

She once again wrote Mio’s name in the book.

Swish—

This time, no blur or static appeared.

Instead, detailed information about the Eurasian Sky Disaster emerged on the blank pages.

”This is...”

Nia carefully read through the content.

It was an event she had personally experienced, but the records in Rasiel were even more detailed.

It included how the three wizards, driven by their desire for revenge against humanity, utilized the Spirit Formula to summon the Spirit of Origin, and the massive destruction caused by the disaster.

It even covered Mio’s true identity.

The Spirit of Origin was neither a lifeform born from nothing nor an alien from outer space.

Instead, she was a magical lifeform formed by the aggregation of natural forces from the Earth’s surface—earth, sky, and sea.

”So that’s how it is...”

The contents of Rasiel were identical to her memories and supplemented many things she had previously been unaware of.

Nia started to believe that Setsuna was not deceiving her.

It seemed that to search for information about other worlds or beings of a higher status than herself, the two of them had to work together.

”What else do you want to see? Should I help you write?”

”Together, we’re like a walking encyclopedia!”

Her mood suddenly improved.

”Hmm...”

Setsuna thought for a moment.

”Help me check on the base. I kind of miss my shipgirls.”

”Let’s see what Yat Sen is doing lately?”

The two of them wrote down Yat Sen’s name together.

On the blank page, an image emerged of a girl wearing traditional ruqun attire with her hair tied in a bun.

She was sitting at a desk, diligently handling various documents.

Perhaps influenced by Setsuna and Nia’s combined power, Rasiel presented the information in the form of a manga.

”Wow, she’s so pretty...”

Nia and Kurumi, who had leaned in to take a look, couldn’t help but admire her.

”She’s working so hard. I should bring her a gift when we get back.”

Setsuna sighed, feeling that Yat Sen was truly dependable.

Thinking of another oath-bound ship, he and Nia wrote down Taihou’s name.

”...”

The scene shifted.

Inside a bedroom, a beautifully shaped shipgirl with twin tails and a seductive face was lying on the bed.

She was hugging a life-sized body pillow, rubbing her face against it repeatedly.

Everyone saw clearly that the pillow was printed with Setsuna’s image.

”Commander-sama, when will you come back to keep Taihou company...”

”I miss you so much...”

Taihou murmured softly as she rubbed against the pillow.

Setsuna: ”...”

Nia: ”...”

The shipgirls: ”...”

Well, that was Taihou for you.

...

...

One day later, after completing their tasks in this timeline, Setsuna opened the space-time passage and led everyone back to their original time period.

[Date A Live World (1988) → Date A Live World (2011)]

Swish—

As they entered the passage, a kaleidoscope of dazzling lights and colors filled their vision.

”Commander, are we really traveling through time?!”

Richelieu was astonished.

In the past, when they used the spiritron transfer device, the farthest they had traveled was a few thousand years back to Chaldea’s singularities.

This was the first time they had crossed time within the same world.

”Of course. Time and space are fundamentally intertwined, and now that we’ve completely altered the course of this world’s story, everything should be different when we return to the future.”

Setsuna glanced at the Spirits beside him and smiled.

Initially, he thought this ability was only useful for traveling between worlds, but after the discovery of the spiritron calculation device, new possibilities quickly emerged.

A space-time passage, as the name suggested, encompassed both time and space.

As long as he anchored a specific point in time, he could return to the past and change the future.

”Hmm...”

”The Spirit of Origin is with us, DEM has been destroyed, and all related records have been erased... So, this world should no longer have any extraordinary powers.”

”Origami Tobiichi’s parents won’t die either...”

Richelieu counted on her fingers, recalling the events of the original timeline.

Suddenly, everyone noticed that on both sides of the space-time passage, the history of the Date A Live world was unfolding like a movie, displaying the changes made to the timeline.

”Oh?! Are we watching how the original story has been altered?”

Setsuna’s interest was piqued as he carefully observed the fast-forwarding images.

After the fall of DEM headquarters, the British government launched an investigation into the mysterious airstrike, but the case eventually went cold.

With MI6’s level of expertise, investigating intelligence from another world was far beyond their capabilities.

With the loss of their leaders, the remnants of DEM fell apart.

Most of the regular employees, who were merely working for a paycheck, scattered once their superiors were gone.

Moreover, with the Spirit of Origin taken away, no new spacequakes had occurred after the South Kanto Sky Disaster.

As a result, AST (Anti-Spirit Team) and Ratatoskr were never established, and records related to Mio, the Spirits, and magic disappeared from history, buried alongside Westcott.

The Eurasian Great Spacequake became an unsolved mystery.

Some scientists theorized it was a nuclear test, while others believed it to be an alien weapon.

Years of debates led to no definitive conclusion.

Then, familiar faces began to appear.

Many girls who had been tricked by Mio into becoming Spirits had now survived in this new timeline.

Among them was Sawa Yamabuki, whom Kurumi had mistakenly killed.

”Sawa...”

Kurumi couldn’t resist reaching out to touch the space-time passage, but Setsuna stopped her.

”Don’t rush. We’ll come back later and bring her over. Mio can grant her a Spirit Crystal—after all, she was meant to be the White Queen.”

Time continued to flow.

In the end, although Spirits possessed immense power, they did not significantly interfere with the overall development of human society in the original storyline. Their conflicts were mainly limited to a few organizations vying against each other.

As a result, within a few years, Spirits became nothing more than urban legends. The subsequent course of history remained largely unchanged—economic growth continued, cities expanded, cars gradually filled the streets, and fashion trends evolved one after another.

Ten minutes later.

Everyone fast-forwarded through these 23 years of history and reached the exit of the space-time passage, arriving back in the 2011 Date A Live world.

They landed in the same suburban park of Tengu City, where the spiritron transfer receiver still emitted a faint glow.

Everything around them was nearly identical to when they had first departed.

”We… really came back?!”

The accompanying shipgirls, Spirits, and Tohru all looked around in a daze.

The experience of traveling through time left them with a strong sense of unreality.

”We’re back.”

Setsuna gestured toward the distant Tengu City.

Looking at the skyline, the buildings appeared much the same as when they left—only now, they seemed a bit more modernized compared to 20 years ago.

Several shipgirls turned on their communication devices to check the latest news, eager to see what had transpired in their absence.

[United States SEAL Team eliminates terrorist leader…]

[Severe drought in the Horn of Africa, Somali pirates running rampant…]

...

The headlines were filled with news that felt very much of their time to Setsuna.

Most importantly, these reports indicated that their intervention had not created any major butterfly effects that drastically altered history.

Feeling reassured, Setsuna activated the Hyperdimensional Star Map and checked the description of the Date A Live world.

The information had changed:

[Date A Live (Pre-Space Age)]

• A world based on modern society with no supernatural forces.

• Nations remain divided, and no unified world government has yet been established.

”…”

”So, from now on, this world will have no Spirits or wizards, becoming a purely technological civilization from the pre-space age?”

Richelieu marveled at the updated description.

Before their departure, the Date A Live world had been a realm of magic.

Thanks to Setsuna’s intervention, it had now transformed into an ordinary modern human society without any supernatural elements.

”That’s right. We have permanently altered this world’s history and future.”

Setsuna nodded with satisfaction.

”Time-space technology—it’s pretty amazing, huh?”

--------------------------------------------------------------------------------------------------------------

40 Advanced Chapters Available on Patreon:

Patreon.com/DaoOfHeaven