Crossover Shipgirls: Building a Dimensional Empire from Scratch

”Ahem, the opportunities left for us are running out.”

After gathering all members of the Konosuba Squad and carefully analyzing the current situation, Iris reached a despairing conclusion.

All the major and minor missions in the Re:Zero world had been swept clean by the other teams.

Whether it was world conquest or recruitment, every task had entered its final phase.

The Great Tomb Squad had marched southward, sweeping through the world like an autumn wind scattering leaves, subjugating everything in their path. They even took care of the Archbishops of Sloth and Greed along the way.

It was foreseeable that the Holy Empire of Vollachia would soon fall completely.

As for recruitment missions, the Demon Slayer Corps and Night Raid Squad had already completed most of them. The remaining targets were scattered and too far away.

”Ugh...”

”We finally got to join an interworld expedition, and we’ve just been eating, drinking, and playing the whole time—isn’t that kind of bad?!”

”Won’t the Commander think poorly of us?!”

Iris clutched her hair in distress.

”Eh?!”

The Crimson Demon lolis crowded around her.

”As long as I’m here, any mission can be completed! I am the great archwizard Megumin!!!”

Megumin pounded her chest confidently.

”I can now use ten—no, twenty Explosion spells a day! They’re even more powerful than before! Hmm, I should call them 12-Core Explosions now? ...Tohru-sama taught me that.”

”...”

”That’s nice and all...”

Though all the Crimson Demon lolis who had studied at the Magic Academy were quite strong, Iris felt that aside from Yunyun, not a single one of them was mentally normal.

Her head throbbed.

”Anyway, we don’t have enough people, so conquering the world isn’t feasible. And the recruitment missions are already taken...”

The most sensible one, Yunyun, joined in analyzing the situation with Iris.

”If we go for the Witch Cult... they’ve basically been wiped out too.”

”The Archbishops of Sloth and Greed were taken out by the Great Tomb Squad, and the rest—Gluttony, Wrath, and Lust—are being dealt with by other teams.”

Under the doctrine of overwhelming firepower, the various squads had efficiently eliminated the Witch Cult and the Archbishops of Sin. Once their positions were located, they were annihilated instantly with super-tier magic from long range.

There was no need for any dramatic battle of wits and wills—the remaining Archbishops would likely meet the same fate.

”Fighting Archbishops isn’t fun anyway! They’re too weak! We should do something truly great!”

Megumin raised her arm passionately, earning cheers from the Crimson Demon lolis around her.

”Yes!”

”Let’s do something amazing!!!”

”...”

Iris’ headache worsened.

She unfolded the map, and the girls crowded around, scanning for any possible target worth their attention.

”Hmm... Looks like most of the missions have already been handled... The magical beasts were wiped out by the Demon Slayer Squad too, guh...”

No matter how she looked at it, there was almost no room left for them to make an impact—especially with the Great Tomb Squad on the verge of global domination.

”Waaaah—Yunyun, why didn’t you tell us sooner??!”

Komori grabbed Yunyun and shook her back and forth.

”I did! You just never listen...”

Yunyun’s expression was lifeless.

Suddenly, Megumin pointed to a location in the eastern desert on the map.

”Here! Let’s go here!”

The Konosuba Squad leaned in to look.

The marked area lay at the far eastern edge of the continent—the Auguria Great Desert.

Deep within the sands stood a bizarre, futuristic structure.

The Pleiades Watchtower.

According to legend, four hundred years ago, the great sage who sealed the Witch of Envy resided there, alongside Lugnica’s guardian deity—the Divine Dragon, Volcanica.

In the original story, the main cast had braved countless trials within the Pleiades Watchtower to save the sleeping Rem.

Within the tower was a library said to hold the collective knowledge of all sages. Each trial conquered granted access to deeper levels of the library, with increasingly advanced knowledge within.

Perhaps because the location was remote, or maybe because the Great Tomb Squad was in a rush to complete their conquest of the world, they hadn’t yet sent anyone to the Pleiades Watchtower.

”The Pleiades Watchtower must contain all the knowledge of this world—especially magic! The Re:Zero world’s magic system is totally different from ours, we have to check it out!”

”Also, isn’t the Pleiades Watchtower related to the Witch of Envy? The three heroes who sealed her were all there.”

The Crimson Demon lolis’ thirst for magical knowledge instantly exploded.

”If we can bring back all the world’s knowledge, and maybe even study the Witch of Envy—better yet, take her with us—that would be a huge achievement, right?!”

”And that dragon too!”

Megumin raised her hand.

”We could tame it as a pet and present it to the Commander! No one else could pull that off!”

”I kind of want to taste dragon meat...”

Komekko muttered softly.

”No, we’re giving it to the Commander, not eating it.”

Megumin lectured the little loli sternly.

”???”

Iris’s head filled with question marks.

The full name of the kingdom was the Holy Dragon Kingdom of Lugnica—its very name made it clear that the nation’s foundation and survival depended on a covenant with the Divine Dragon.

And these little lolis were seriously planning to capture the kingdom’s guardian deity either as a pet—or for dinner?

Indeed, not a single Crimson Demon had a normal brain.

”Can we... even do that?”

The princess was stunned.

”Why not?! The Commander would totally do the same thing if he were here!”

”Besides, we’ve been doing nothing but eating and playing this whole time. If the Great Tomb Squad conquers the Pleiades Watchtower first, we’ll really have nothing left to do!”

The Crimson Demon lolis chirped noisily around Iris.

As for the rest of the Konosuba Squad—Darkness, the girls from Axel Hearts, and others—they all joined in trying to persuade her.

”Your Highness, didn’t you just say you wanted to do something grand? What could be grander than conquering the greatest repository of knowledge in this world—and gifting the Commander a dragon?”

”Uh...”

Iris held her head, lost in thought.

She hesitated.

”...Conquering the Pleiades Watchtower would be amazing, but I feel like we don’t have enough people. If we get into trouble and the Commander has to come save us, wouldn’t that be embarrassing...?”

”Well...”

Yunyun rested her chin on her hand, recalling something.

”Maybe we could bring in some help? I saw an acquaintance in the city a few days ago—she seemed to be here on vacation...”

”She’s pretty strong. Maybe she could help us out?”

...

Half an hour later.

On a city street, Iris and the Konosuba Squad stood blocking the path of a gray-haired, red-eyed girl.

”Excuse me, are you the Herrscher of Sentience?”

”We’d like to ask for your help with something.”

Iris politely greeted Senti.

Though she had also joined the interdimensional expedition, the Herrscher of Sentience wasn’t interested in world conquest. She simply wandered around, sightseeing and relaxing.

”?”

The Herrscher of Sentience lowered her snack, scanning the Konosuba Squad and the group of lolis crowding around Iris.

”What?”

”I’m not part of your expedition. I’m just here to play. Don’t even think about making me work overtime.”

”Uh...”

Megumin leaned forward.

”We’re going to challenge the Pleiades Watchtower and maybe capture the Divine Dragon Volcanica. Could you lend us a hand?”

”...Huh?”

”Are you guys insane?”

The Herrscher of Sentience blinked, utterly baffled.

She’d heard rumors that the Crimson Demons were eccentric, but seeing it firsthand was something else entirely.

”Guh—”

Iris choked on her words.

”Please~ pretty please~”

The Crimson Demon lolis rushed forward, hugging Senti’s legs and clinging to her like koalas.

”Great Herrscher of Sentience, please help us!”

”We beg you~~”

Judging by mental maturity, Senti wasn’t much older than the Crimson Demon lolis—but she did look a bit more grown-up.

She had spent so long in the capital that no one had ever called her ”Great Herrscher of Sentience” before.

Usually, she either got scolded by old relics or teased by the Commander as a kid.

But this—this felt good.

Ahem—

Lost in a chorus of loli admiration, Senti’s ego soared.

”Very well, the Great Herrscher of Sentience shall lead you to victory.”

...

Shua—

One teleportation spell after another flared to life.

The Konosuba Squad and Senti leapt continuously through space, jumping from one point to another across the vast terrain.

During their time training at the Magic Academy, the Crimson Demon lolis had learned all sorts of strange and questionable spells—including short- to mid-range teleportation.

Senti couldn’t help but watch in surprise.

”Oh, not bad. I remember the old fossils couldn’t do this. You girls haven’t been in the Starsea Empire for very long, have you?”

”This is the innate talent of the Crimson Demon Clan!”

Megumin puffed up her chest proudly.

”However, our mastery of this spell isn’t perfect yet. When teleporting multiple people, there’s only about a fifty percent success rate.”

”Fifty percent? So one success out of two attempts?”

Senti thought that wasn’t too bad. The Konosuba Squad had plenty of supplies and mana anyway.

”No, I mean we can only teleport half of a person.”

”???”

”Wait, what?!”

Buzz—

The world blurred for a moment, and when their vision cleared, they found themselves standing in a vast desert that stretched as far as the eye could see.

Ahead of them stood a towering white structure that pierced the clouds—a massive central pillar surrounded by several smaller ones, all extending upward into the sky.

Faintly visible above the clouds was what looked like a platform.

”We’re here!”

Senti checked herself—thankfully, no missing parts.

”Whoa...”

Everyone gazed up at the distant Pleiades Watchtower.

Majestic and solemn, its design looked completely alien to this world—instantly exuding an aura of supreme importance.

”Feels like it’s packed with treasure inside.”

”Quick, quick, let’s go—!”

The Crimson Demon lolis had terrifyingly high energy levels. The Konosuba Squad quickly marched—no, charged—toward the Pleiades Watchtower in noisy excitement.

Normally, the road to the Watchtower was filled with trials.

The greatest obstacle was the hordes of magical beasts roaming the desert.

Few ordinary people from the kingdom ever reached the Watchtower alive—returning from the attempt was already a miracle.

And then there was the sage’s disciple, Shaula, who hunted anyone who approached the Watchtower.

However, for this overpowered group of lolis, none of that posed even the slightest threat.

”Chain Lightning Dragon!—”

”Skyfall!—”

Boom! Crackle!

After a barrage of explosions and lightning strikes, every magical beast was either reduced to ashes—or became Komekko’s dinner.

Before long, they arrived at a spot a short distance from the Watchtower and came to a stop.

”Hmm... According to the data we gathered, to conquer the Pleiades Watchtower, we have to ascend floor by floor.”

Princess Iris opened her holographic interface, discussing the strategy with her team.

”The Pleiades Watchtower has seven floors, each named after one of the stars of the Pleiades Cluster.”

”From the third floor upward are the trial zones. Each floor holds an exam—passing it grants access to that floor’s library. The higher the floor, the harder the exam, and the more advanced the knowledge inside.”

”The third floor is overseen by the Sage, the second by the Sword Saint Reid Astrea, and the Divine Dragon Volcanica guards the first...”

As the leader of the Konosuba Squad, Iris was likely one of only two people who had actually done any prep work before departure.

She had thoroughly studied the Re:Zero world beforehand.

”So, we’ll need to choose the best candidates for each trial, and as for the exam questions...”

”Also...”

Just as she was deep in thought, trying to devise a detailed strategy—

The Crimson Demon lolis huddled together, whispering excitedly for a few seconds before each drew their staffs and magic scrolls.

They spread them out on the ground, taking up battle positions.

”What are you doing?!”

Iris was startled.

”We’re going to conquer the Pleiades Watchtower, duh. Are you an idiot?”

Megumin gave her a look of pure pity.

”Who’s going to waste time following their rules and climbing floor by floor?”

”We’ll just blow up the Watchtower’s barrier from outside, teleport in, grab what we need, and leave! Way simpler!”

”???”

Iris’s head filled with question marks again.

And yet... she couldn’t deny that Megumin’s logic kind of made sense.

She wasn’t sure whether the Crimson Demons were crazy—or if she was.

”The Pleiades Watchtower’s trial rules prohibit destruction. Participants must follow the official procedures...”

Yunyun reminded timidly.

”Rules are meant to be broken!”

The other Crimson Demon lolis dismissed her concern entirely.

”If the Commander were here, he wouldn’t waste time climbing floor by floor either!”

”Ah, it’s been so long since I last used Explosion Magic—I’ve missed it~~”

”I’ll go first!”

Megumin rubbed her staff lovingly, unrolling her magic scrolls as she chugged several potions to boost her spell power and stacked a ridiculous number of self-buffs.

”Major Mana Amplification, Medium Fire Enhancement, Arcane Power Boost, Mystic Amplifier...”

Just the buff names alone exceeded twenty. The others’ heads spun listening to her chant them all.

Her passion was Explosion Magic. Her special skill was Explosion Magic. Her hobby was Explosion Magic. Her one and only true love—Explosion Magic.

As such, everything she had learned in the Starsea Empire was for the sake of unleashing a stronger Explosion spell.

Striking a dramatic chuunibyou pose, Megumin stood tall as the other Crimson Demon lolis cleared the area around her.

”Hmm... This distance should be about right—shouldn’t get caught in my own blast.”

She measured the range and, with exaggerated flair, began her incantation:

”Darkness blacker than black and darker than dark...”

”By the name of the Crimson Demon, I declare the primal collapse! O you who dwell in the root of all power, gather before me in this land of the world’s end!”

”EX-PLOSION!!!”

BOOM—!

For an instant, the entire world fell silent.

Then—a blinding beam of light erupted from the base of the Pleiades Watchtower, engulfing everything nearby in searing radiance.

A gigantic fireball painted the sky crimson. Even several kilometers away, the Konosuba Squad felt the scorching heat wave, hurriedly casting barrier spells to shield themselves.

The fireball swelled rapidly, compressing the air into a deafening shockwave. A massive mushroom cloud rose into the sky, blotting out the sun.

RUMBLE—!

With that single blast, the ground itself trembled. The auxiliary buildings surrounding the Pleiades Watchtower were obliterated instantly—only the central structure barely remained standing.

The terrain for several kilometers around had been literally shaved flat.

”???”

”When did your Explosion Magic become that powerful?!”

Senti was stunned. She remembered Megumin as just a kid who liked throwing around flashy explosions.

”This is the ultimate destructive spell—an upgraded version of Explosion Magic! Enhanced through thirty-two layers of skill buffs! Nuclear Explosion Magic!”

Megumin patted her flat chest proudly.

”...Though the Commander did call this kind of buff-stacking before a spell ’monkey play.’ Said it’s just for showing off big numbers...”

”...”

”Let’s just hope you didn’t blow up all the treasures inside...”

Iris sighed, rubbing her temples.

”Not enough! It’s not enough!! The barrier’s still up!!!”

The other Crimson Demon lolis shouted.

”There are enemies inside!!!”

They began chanting one bizarre spell after another.

BOOM—!

RUMBLE—!

Blast after blast slammed into the Pleiades Watchtower.

If not for its divine protections and absurd durability, the structure would’ve been reduced to dust dozens of times over.

Even so, under the relentless bombardment, it now looked dangerously close to collapsing.

Half an hour later.

The group finally approached the tower’s base. Megumin used a peculiar detection device to scan the area.

”Alright, the teleportation suppression effect is gone. There shouldn’t be any threats left inside.”

”Lock onto the target—we’ll hit the Grand Library first, then go find the Divine Dragon...”

Crash—

Crackle—Crack!

From the ruins of a nearby collapsed structure, a girl crawled out.

Barely dressed—almost half-naked—she had brown hair, green eyes, and a long scorpion-like braid trailing behind her.

Her cloak and outfit were tattered from the earlier blast, her beautiful face smeared with dust and grime.

She staggered to her feet, shaking her head to clear it, then glared furiously at the stunned Konosuba Squad.

”Who... used magic to attack me just now???!!!”

”Once or twice I could tolerate it—but three times?! Are you out of your minds?! Can’t you people follow the rules and take the trials properly?!”

”Come here and die already!!!”

”Uh...”

The Konosuba Squad exchanged awkward looks.

As expected, this furious girl was none other than Shaula—the disciple of the Great Sage Flugel and guardian of the Pleiades Watchtower.

She had stayed here all these years to protect it.

”What do we do with her?”

Yunyun nudged Iris.

”I’ll handle it.”

Senti stepped forward, raising a finger toward Shaula.

”The Herrscher of Sentience rewrites your consciousness.”

”Shaula, you’re free now. Go report to the Commander.”

”Ah... oh, okay.”

The girl’s expression went blank for a moment.

”?”

The Crimson Demon lolis were in awe—Senti’s ability was just too cool.

”Alright, let’s go find the Divine Dragon and the Sage. I’ll cover you.”

—

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