I Am the Weakest of the Four Heavenly Kings but the Demons Are Obsessed With Me - I Am the Weakest of the Four Heavenly Kings but the Demons Are Obsessed With Me chapter 18

18 – Basic Magic Theory Chapter 1: The Principle of Magic

I have a friend who has been with me since very early childhood. His name is Brown, a teddy bear.

For me, Brown is not an ordinary doll. It was a precious gift my mother made herself when I was young.

As I grew older, I no longer carried the teddy bear everywhere, but whenever I stayed somewhere for long, Brown was always with me. This did not change even in the dormitory of the academy.

Holding the ragged-looking bear, sewn with unskilled stitches.

I was deep in thought.

“…Uh, Brown. How should I apologize…?”

My father was a man who bowed his head politely to people of lower status than himself. Through him, I learned that the most important thing in an apology is sincerity, and protocol comes second.

However, the human heart is not so simple. Every time I thought of apologizing, strange discomfort and awkwardness rushed in, making it hard to sort out my thoughts.

So I began to think more.

What would be the right timing to apologize? What if they feel it’s a grudging apology? What if they don’t accept my apology? What if they demand something in return for accepting my apology?

My thoughts spun on, like a cat chasing its tail. My mind got complicated. After burying my face in the doll and holding my breath for a moment, I raised my head and let out a suffocating sigh.

I shrieked alone, then belatedly looked around, answering the hesitations coming from the next room, and put my ear to the wall to make sure it was soundproof. I breathed a sigh of relief when I heard nothing.

And then, hugged the doll again and pondered a long time.

I thought of a person.

“…What would that person have done?”

The day I parted with my father.

A man with a mask who took me, a young child, to King Ruskin.

The time I spent with that man wasn’t long. He was a competent guide and wasn’t bothered by carrying a doll-hugging child around.

A person good with children. A kind person. And a curious person. The man in my memory left that impression. He reminded me of a devout priest in a bustling city.

He was disciplined but easygoing, formal but friendly, discerning but not strict.

It seemed he put more effort into comforting a crying child than into taking me to King Ruskin.

I, young and immature, lashed out my grief of parting from my father at this man. Even knowing that he was simply trying to help me, I behaved like he had stolen my father.

In those moments, the masked man would soothe me with a smile and a pat on my head. And when I slapped his hand away saying ‘Don’t touch me’, he would gently fold his hands and apologize to me.

– “Oh dear, I’m sorry, Miss Rosa. I overstepped with a lady. Will you accept my apology?”

– “… Humph. I’ll let you off this time.”

– “Thank you, Miss Rosa.”

“…I’m also… sorry for getting angry…”

“Huh, what did you just say?”

“…I don’t know! Idiot!”

It had only been a week. In just one week, the man had taken me to the Duke of Ruskin. And then, like a mirage, he vanished.

Like the imaginary friend of a young child that disappears as one grows older, he too disappeared just before I came face-to-face with the Duke of Ruskin.

And when I reached into my pocket to pull out the letter my father had left for me to give to the Duke…

In the pocket lay my father’s letter, along with a piece of candy and a handkerchief.

I unwrapped the candy and popped it into my mouth. It was sweet. As the candy melted in my mouth, a lump formed in my throat.

I held the handkerchief in my hand and stared at it blankly. It was the handkerchief the man had used to wipe the tears from my eyes whenever I cried. Occasionally, I had even used it to blow my nose.

Only then did I realize I was crying again.

“Sniff…”

That man, even after he disappeared without a word, continued to wipe away my tears.

I didn’t know any other way to interpret his sweet and warm farewell.

Even today, more than ten years later, on nights when I’m lost in thought, the memory of that day always resurfaces.

“…Before the lecture starts tomorrow, I must apologize to Professor Plumm.”

With that indistinct resolution, addressed to no one in particular,

I stopped worrying and lay down on the bed.

The warmth of brown I held was comforting. Somehow, I had a premonition that I would have a good dream.

Goodnight.

Brown.

*

“Professor─”

“The stillness of dawn’s twilight. The silence after a curtain call. Silence.”

The clamor of the lecture hall quieted down in an instant. All eyes were on me.

It wasn’t an ordinary magic, but a demonic magic using mana. The spell dissipated quickly, allowing speech again, but the silence that had settled in was as solid as ice on a lake.

I nodded lightly, meeting the gaze of everyone in the room, and greeted them.

“I introduced myself once before, but let me introduce myself again. I’m Plumm Orchid, and I’ll be teaching you magic.”

“…What kind of magic was that just now?”

Apparently, there was a student with enthusiasm. The question came in even before I had finished greeting.

I had anticipated this kind of question since the moment I cast the spell. After all, for most of the students, it was a magic they had never seen before.

It’s silence. A spell that silences the voices of the surrounding creatures.

“…Perhaps, this is.”

“You might be guessing correctly. This is a magic of the demon tribe that I can use because I am half-human, half-demon.”

Some students gasped. Others trembled slightly.

And then.

Many students’ eyes sparkled with curiosity.

It seems like I’ve buttoned the first button correctly.

“I intend to teach you the magic of the demon tribe.”

Silence lingered in the classroom for a while following my startling declaration. It was a longer and heavier silence than when I used the silence spell, dominating the space.

This silence was exactly what I had hoped for. Teaching is a form of communication, and I had managed to seize control of that communication’s breath through a slight shock.

Now all that was left was to push forward.

“Of course, as you all know, it is impossible for humans to use demon tribe’s magic. The source required to complete the magic is different. The magic of the demons, which uses ‘demonic energy,’ and the magic of humans, which uses ‘mana,’ have evolved independently through completely different processes. In terms of principles, structure, and composition, the magic of the demon tribe and that of humans are entirely different… This is the common knowledge we hold.”

I’ve been acting as a spy in the demon world for the past few years, doing quite a lot of things. I’ve helped the hero’s growth, picked apart the social structure of the demon world, and set the groundwork for the victory of the human realm.

But those weren’t the only things I did. For me, a half-human, half-demon, the demon world was also an efficient training ground to wield my ‘half-demon’ abilities.

Naturally, I learned the magic of the demon tribe without discrimination. Even the grand spells I couldn’t use due to the limited output as a half-demon, I learned in theory.

During this process, I discovered quite an interesting fact.

“From now on, you may disregard all that common knowledge. Humans cannot use the magic of the demon tribe, but they can utilize it. I will show you an example of this right away.”

The first magic I would show is one everyone is likely familiar with.

Mana contained in my heart gathered at my fingertips, drawing a magic circle composed of complex geometric shapes.

I chanted softly, yet with a deep and clear voice that all the students in the lecture hall could hear.

“That which becomes more distinct with each cycle. Like the north wind of the frozen lands or the frost of dawn. In the polar regions, all freezes, and the eternal snows of the sacred peak and the frozen north shall not thaw. Cooling.”

A cooling spell to lower the surrounding temperature. A spell that becomes more effective the higher the ambient temperature is.

While the effect was not so pronounced in the current room temperature, it was enough to lower the body temperature of the students.

As the students’ tensions heightened due to the drop in their body temperatures,

I used a new spell. A spell that uses demonic energy, not mana.

My demonic energy flowed through my veins and stretched out like threads from my fingertips, branched out from a large stem into smaller ones, creating a dendrogram reminiscent of the vascular system of some creature.

“That which becomes more intermixed with each cycle. Like the warm wind of the ocean or the mirage at the height of noon. In the desert, all parch, and the eternal snows of the sacred peak and the frozen north too shall melt and scatter. Heating.”

As the chant, similar yet clearly opposite in meaning to the previous one, came to an end.

“Those who are hot may take off their outer garments.”

Contrary to the previous cold, the lecture hall had become stifling hot, as if the chill had been a lie, making it hard even to breathe.

Due to the abrupt change in body temperature, several students complained of dizziness. If the magic continued unchecked, the temperature would keep rising infinitely, but I did not possess enough magical energy to sustain the spell for long.

As the magical energy maintaining the spell dispersed, the temperature in the overheated classroom gradually decreased. A few students exhaled sighs of relief.

I tapped the blackboard with my fingers, once again gathering the students’ attention.

“I told you at the beginning, didn’t I? Magic of humans and magic of the demon kind are completely different in terms of principles, structure, and composition. Now, it’s alright to erase ‘principles’ from that statement.”

I began writing on the blackboard. The content wasn’t particularly meaningful.

It was, so to speak, a kind of… declaration.

[Basic Magical Theory]

[First Lesson]

[Principles of Magic]

The declaration that I would fully drill these contents into their heads.

That kind of declaration.