Otherworld Demon King Survival Guide

I died and woke up in another world.

The name of this world was the Demon Realm.

Did I die and go to hell? I thought so, but it wasn't a mistake; it was reality. The Demon Realm was a hellish place. The name alone signified it. I was reincarnated in this Demon Realm, which was utterly different from Earth.

"Wow."

It was so unbelievable that I still couldn't quite accept it. Even though I knew what happened, it was still surprising.

A world where winged monsters and other creatures lived? This felt like something out of a movie with demons and demon tribes. And the fact that I was reincarnated here was unbelievably fascinating.

The Demon Realm was a dreadful world inhabited by various malevolent races.

The vast world was mostly shades of purple, red, or black, and each demon tribe fought desperately to maintain their territories.

"It's a world completely different from Earth."

I heard that beyond this dimensional barrier, there was a place called the "Middle Realm" where humans and other races lived. There was even a place called the "Great Heavenly Realm" where angel-like beings lived, but I didn't know much about that.

What I did know was that the Demon Realm and the Great Heavenly Realm were at war.

I hadn't even been awake for a year to become immersed in this world's language, so I hardly knew anything, even though I was about 9. Because I couldn't speak well, I couldn't go anywhere.

My world was confined to the interior of this massive fortress.

Anyway, I was born here as the son of a demon named Duchess Keraxis.

"I was even born from an egg."

Like some great legendary figure.

…

"I'm still amazed that I was born from an egg."

I looked at the sky while sitting on the windowsill.

Instead of the sun, a giant evil-looking eyeball was floating in the sky, and the sky was purple. Gargoyles, instead of pigeons, were flying around in the purple sky.

Below was the jagged landscape of a city.

"What the hell am I?"

I may have reincarnated as a demon, but I knew almost nothing.

That was the problem. Because I had reincarnated, my memory wasn't wiped, which made learning the Demon Realm language a big issue.

There was a huge difference between a newborn baby learning their native language and a person who was Korean learning the Demon Realm language.

"I'm an idiot."

So, I had been living in this massive fortress as an idiot, unable to even speak properly.

"Really, an idiot."

At least last year, I finally became capable of conversing, but… it was too late now. I was 9 years old and seriously lacked the common sense or knowledge that demons should have.

I had seriously dedicated everything to learning the completely unfamiliar language of the Demon Realm, but in the end, I was still far behind my peers.

"Damn it."

Thinking about it just pissed me off. Why did I have to reincarnate? If I had no memories, I would've just lived as a normal demon.

I couldn't help but sigh.

Why did I have memories even though I had reincarnated? Did the soul really exist, and was a person's consciousness one with that soul?

My concerns only deepened.

Demons were considered adults when they turned 10.

And I was 9 years old.

I didn't know what would happen in this evil and cruel world when even the label of being a child disappeared.

"I'll probably be dragged into the battlefield and used as cannon fodder."

I might not know much, but I knew that much.

The protection of children ultimately served to eventually utilize them as troops. A guy like me would undoubtedly become a low-ranking soldier and fight against the angels of the high heavens.

"Let's work out."

The only thing I could do right now was some simple exercise. Since I was not a human but a demon, my body already developed a few years ago to that of a human adult. But I was not that strong.

I was weak.

For demons, the most important thing could be said to be magical power—evil energy that enabled the use of things like magic.

But I hardly had any of it.

My magical power was as small as a rat's tail.

Even worse, I didn't even know how to grow this magical power. How could I learn when I couldn't even speak the language? That was why I was weak. My physical abilities were just average, but my magical power was below that… I couldn't think of anything other than saying that things were really screwed up.

"Ah, seriously."

I immediately started exercising.

If I didn't do this, I couldn't hold on. Even if I trained my body, magical power was the most important thing for demons… I really didn't know what would become of me.

"Hoo! Hoo, damn it!!"

I focused on strength training in the small room assigned to me. I was out of breath. My deepening concerns… I pushed those thoughts to the back of my mind and bore the pain of strength training.

How much time had passed?

"Ah-haak!"

Finally, I finished my workout.

My body was soaked in sweat.

"Hoo… Mirror. Mirror."

I went and stood in front of the mirror.

Aside from having snow-white skin, somewhat long ears, and horns, the thing in the mirror didn't differ much from a human.

That was the kind of demon I was.

Fangs longer than a human's teeth were visible when I opened my mouth. This wasn't a vampire thing. Even my pupils were vertical. My hair color was pitch black.

"Damn demon."

Still, my body and face were at a decent level.

"I like it."

I was about to punch the mirror but stopped. At that moment, I decided to head into the small attached shower room to wash up.

Knock, knock.

Someone knocked on the door.

"Yes? Who is it?"

What was going on? Who had come to my room? To the best of my knowledge, no one had ever sought me out like this. Even the maids inside the fortress had ignored me lately, so I had been flying under the radar.

Who could it be if no one I knew would come looking for me?

Creak.

The door opened even before I could unlock it.

Simultaneously…

Whoosh.

A refreshing fragrance seemed to flood the room.

The person who entered was…

"Kyuse Bellacruel. Is that correct?"

A woman with short, pitch-black hair, slightly taller than my near-180 cm height, walked in. She had the typical bewitching beauty of a demon, but what mattered right now wasn't the visitor's looks.

"Yes, yes. Kyuse Bellacruel. That's me."

Her horns.

Her horns were pretty large.

I had grown up within this fortress along with others my age. So there was one thing I knew for certain: those horns.

The larger the horns of a demon, the better.

It signified strength.

The horns of this visitor were larger than any other horns I had seen around me. Really, they were as big as those of a bull… This was clearly someone of high status.

"But who are you?"

I asked formally, bowing slightly at the waist, raising my shoulders a bit, and bringing my hands together to portray a humble demeanor. She appeared even more formidable than the demon world teachers who taught groups of kids.

In the demon world, the strong ruled.

"…"

The visitor didn't answer my question and stared intently at me.

"You're my younger sibling? This is a summons from our mother, the Duchess. Prepare and come to this place."

Saying that she handed me something like a pass and a map.

"Yes. Understood."

I reflexively accepted these items very formally.

But I was her younger sibling?

Could she be my older sister?

Ah, that made sense. Most of the demons in this region hatched from the eggs laid by our mother, the Duchess. So we're definitely of the same bloodline… But it was a bit weird for her to treat me like a younger sibling.

However, I didn't have the guts to ask any questions. My audacity wasn't big enough to speak first to a demon with such large horns.

"Then, I'll be going."

Since her business was seemingly done, the visitor turned to leave. I didn't even get to hear her name before she vanished.

…

Left alone, I muttered,

"Uh."

What the hell was going on?

The Duchess?

"Our mother, the Duchess, has summoned me?"

My mom had called for me.

Duchess Keraxis Nainchel Bellacruel.

That was the name of the demoness who gave birth to me.

You could call her my mom.

"Mom."

The Duchess Keraxis, the owner of this large demon duchy. I had only seen her face maybe twice.

She was beautiful enough to be called a goddess.

With pitch-black hair and matching large horns… A sensual figure. A demoness possessing an absolutely bewitching beauty fitting for her kind.

She could be called a dark goddess. Her striking beauty was unforgettable. It must be instinct, as one born as her child would naturally have this kind of tendency.

"…"

She was one of the few dukes in the demon world and rumored to be really strong. Cruel. Amazing. Given her abilities, it was no surprise that she owned a large territory in the demon world.

Her power came from her eggs.

As far as I knew, Mother Duchess was a hybrid of a succubus and Baphomet. So she lays eggs all by herself, without a spouse. Most of the beings living in the duchy hatched from those eggs and could be considered her subordinates.

"That's why I've hardly ever seen her."

Mother Duchess lays quite a lot of eggs. But those eggs also had grades. Low-grade eggs go directly to the hatching facilities. Breeders of the same bloodline incubate them and send them to appropriate places for education, using them as members of the duchy.

However, if the egg was high-grade, Mother Duchess personally managed it. She carefully nurtured the egg, maybe even infusing it with her magic. I understood that strong demons were born from such eggs.

"Hmm."

I saw her once when I was born.

I vaguely remember struggling in the darkness when a light appeared, and in front of it sat a demonically beautiful woman.

That was the first time.

The second time was years ago when I was grouped with my peers. She gathered numerous demon children and said something. I couldn't understand the demon language at the time, so I don't know what she said.

That was it.

The times I had seen Mother Duchess.

But now, such a person has summoned me.

"Is there really no reason?"

Why would she call me?

Although I didn't know, given that she laid numerous eggs and treated her children like tools, the notion of 'child' wouldn't be that special to her. Children from low-grade eggs lived their lives without ever seeing her face, they said.

"Why did she summon me?"

Let's try to deduce the reason.

The reason to call me was… There was almost none. But I had seen her face once when I was born. That meant…

"Was I a relatively high-grade egg?"

But why the hell was I so useless?

Why was my magical power non-existent?

I couldn't understand.

"Damn."

Anyway, I looked at the map and the pass in my hand.

"If Mom calls, I have to go."