Peak Between Two: Mushoku Tensei

-Luciel Greyrat-

I wouldn't be reckless.

Getting stranded in an unknown land without sufficient resources was a fatal mistake. Even in the modern world, someone lost in the wilderness needed a solid survival plan before attempting to seek help.

This wasn't just about finding the nearest city.

In this world, people could be far more dangerous than monsters.

This world was set in a medieval era, and if I analyzed it through the lens of history, it was essentially the Dark Ages—a time of instability, weak laws, and power determined by brute strength.

If we ran into the wrong people, Norn, Aisha, and I could be enslaved, robbed… or worse.

That meant before interacting with anyone, I needed to prepare for everything.

In the modern world, money was everything.

But in this world, valuable trade goods could sometimes be worth more than gold coins.

With that in mind, I started gathering materials that could be sold or traded once we reached civilization.

Monster pelts – The thicker and more unique, the higher the value. Bones and fangs – Useful for crafting weapons or tools. Hides and horns – Some monsters had tough skins that could be used for light armor.

However, collecting wasn't enough.

To maximize value, I needed to preserve these materials properly.

Using earth magic, I shaped a crude knife—sharp enough to cleanly skin monsters and avoid damaging the valuable parts.

Three Days of Hunting: Understanding the Local Ecosystem

After three days of hunting, I gathered a decent supply of resources.

Through observation and experience, I learned the ecology of this region.

The creatures I encountered varied from easily manageable to strategically challenging.

Acid Wolves – Their corrosive saliva could melt weak metals. Their flesh was poisonous, but their fur was thick and valuable.

Giant Sand Serpents – Burrowed under the desert, striking at incredible speeds. Their fangs and hides could be sold for high prices.

Black Desert Birds – Fast and aggressive, but their eggs were highly nutritious and edible.

I experimented with different magic types to see which worked best against these creatures.

Earth Magic was effective against soft-bodied creatures like sand serpents.

Fire Magic worked well against acid wolves, but I had to be careful not to destroy valuable materials. I

ce Magic slowed down black desert birds, making them easier to target.

I didn't hold back in my hunts.

Because this wasn't training.

This was survival.

Besides hunting, I used this time to experiment with magic and science.

One of my theories revolved around explosion magic—based on molecular reactions I studied in my past life.

Hypothesis: If I could manipulate the elements in the air, I could enhance combustion, making my fire spells far more powerful.

To test it, I moved far from Norn and Aisha and created a small fireball in my hand.

I slowly increased the oxygen concentration around it—

BOOM!

A small explosion erupted, sending sand flying in all directions.

I grinned.

The theory worked.

By controlling air composition, I could make explosive magic more efficient without wasting excess mana.

I needed to develop this further.

Magic shouldn't just be reciting spells.

If I could combine scientific principles with magic, I could create something never seen before in this world.

That night, I sat near a small campfire, watching over Norn and Aisha as they adjusted to this new environment.

"Is there more food?" Aisha asked, her eyes sparkling with hunger.

I smirked and handed her another perfectly roasted piece of black desert bird meat.

"You were scared to eat this before," I teased.

Aisha pouted. "But it's delicious!"

Norn, quieter as always, ate without complaint, her expression satisfied.

I patted their heads, relieved to see them enjoying their meal despite our circumstances.

At least, for now, they still had something to smile about.

I gazed into the fire.

"I have to get them somewhere safe. I won't let them grow up in a place like this."

Tomorrow, we would move toward the nearest city.

And our true journey would begin.

###

I woke up before dawn, the desert air still carrying the last traces of the night's cold. The sand beneath my bare feet felt cool, a stark contrast to the scorching heat it would radiate once the sun fully rose.

The past few days, my mind had been plagued with thoughts of the village and my family.

Was Mother and Father safe? Was Sylphiette still in the village? Had they already realized that Norn, Aisha, and I had vanished without a trace?

I took a deep breath.

I couldn't think about that now.

If I let myself dwell on uncertainties I couldn't verify, I would only waste precious energy.

Right now, my sole focus was survival—and protecting my sisters.

Under the faint glow of the rising sun, I examined my small frame.

Compared to Rudeus, I was more athletic, thanks to my training with Father. But in this world, I was still too thin to be considered a real fighter.

"This isn't an ideal body for surviving in a harsh world."

Taking another deep breath, I began my morning training routine.

Since there were no gyms, no modern equipment, I had to get creative.

But unlike my past life, in this world, I had magic.

Bodyweight training – I used large rocks as improvised dumbbells, lifting them repeatedly to build arm strength.

Sprinting on sand – Running on loose ground was far more difficult, forcing my leg muscles to work harder.

Push-ups and planks – I incorporated one-handed push-ups to improve core stability and endurance.

Normally, such extreme training would leave a person exhausted for days.

But I had a shortcut.

Placing a hand on my chest, I channeled mana, targeting my damaged muscle fibers with healing magic.

In a matter of minutes, the fatigue vanished completely.

I smirked.

"With this method, I can train faster than normal humans."

After finishing my training, I returned to the small cave where we had taken shelter.

But the moment I entered—

I was met with determined stares from Norn and Aisha.

I blinked. "...What's with those faces?"

Something was off.

Norn was clenching her fists, while Aisha bit her lip, as if building up courage to say something.

Then, in perfect sync, they both spoke:

"Big Brother Luciel… Please teach us how to fight!"

I froze.

...What?

Kneeling down to their level, I studied their faces carefully.

I needed to confirm that this wasn't just an impulsive request.

"Norn, Aisha… Are you serious?"

Aisha nodded immediately, while Norn hesitated for a second before answering.

"Yes! We… don't want to be burdens anymore!"

I remained silent.

Aisha clenched her fists. "Big Brother always protects us… But what if something happens to you?!"

Norn lowered her gaze. "If you get hurt… or if you're not there… we want to be able to protect ourselves."

I stared at them.

A strange feeling welled up in my chest.

To me, they were never burdens.

They were the reason I kept pushing forward.

But… they were right.

This world was too cruel for them to remain weak.

Taking a deep breath, I placed my hands on their heads.

"Alright," I said.

Their eyes lit up.

"But," I continued, "there's a condition."

They straightened up, listening intently.

"Whatever I teach you, you must follow through completely. No complaints. No slacking. If you truly want to learn, you need to commit."

Norn and Aisha exchanged glances before nodding firmly.

"We promise!"

I smirked.

"In that case, let's begin your training."

I wasn't going to teach them mindless brawling.

I needed to ensure they understood the core principles before diving into physical training.

Taking a small stick, I began drawing a diagram in the sand.

"Fighting isn't just about punching or swinging a sword."

I drew a triangle, labeling each point.

Speed – The faster you move, the harder it is for enemies to hit you.

Technique – Even a strong person can lose if they have poor form.

Strength – This isn't just about muscles, but using energy efficiently.

"If you only rely on one of these, you won't last in a real fight. That's why you need balance."

I glanced at them.

Norn was deep in concentration, while Aisha looked excited, though slightly confused.

I chuckled.

"Alright. Let's start with something practical."