Breakthrough with the Forbidden Master [Chapter 4 – Encounter]

Both my parents hailed from commoner stock. It appears they were childhood sweethearts who attended the academy together, only to both be chosen as members of the Hero's party... Well, some events transpired, leading to their marriage and my subsequent birth. This elegant mansion, to put it simply, was constructed after their union. Furthermore, it boasts a vast exhibition hall, typically kept locked, housing an impressive collection of both ancient and modern weaponry and magical artifacts. Within, swords and armor are displayed in showcases or mounted upon the walls. It's likely a personal indulgence that my father, a magic swordsman, amassed numerous weapons after his marriage. He professes to have mastered every conceivable martial art, yet I've never once witnessed him wield a Spear or a Halberd. However, at the far end of this armory-like exhibition hall stands a formidable, thick door. This chamber, accessible only once a year, contains the very treasure that reshaped world history and secured humanity's salvation.

“Now then, Little Man. While I fetch some cleaning supplies, do venture inside and revisit your childhood. If you wish to pilfer it, by all means, try your best. Though, it's quite impossible for a mere half-pint to dislodge the sword sealed upon its pedestal.”

“I'm not stealing it! It's just... well... I wonder what it will be like to behold it again now...”

Sadiz offers this with a smile. Feeling rather awkward, I proceed to unlock the door with the key she provided. The chamber within unfolds into a perfectly square space. A pentagram magic circle is inscribed upon the floor, and at its very center, a sword is firmly embedded in a pedestal.

“...... The Hero's Sword...... The world's mightiest... Hmm?”

A room unveiled only annually. Having missed its opening last year and the year prior, this marks my first entry in several years. As I gaze upon the sword...

“...... Huh?”

Instead of the sword, my attention is captured by something else entirely.

『Hmm... the door has opened... I perceive, 'tis been a year... How many times now... roughly fifteen occurrences...』

These words are not my own. The sealed room should be entirely vacant, as it remains locked year-round with no one permitted entry. Yet, before I even stepped inside, someone was already present.

『...... Hmmm!?? This individual... ah... Hiro's offspring... was but a babe, now a little grown and bearing a striking resemblance to Hiro.』

“No, who are you!! Why are you here?”

『...... What?』

Wait, why is *he* surprised? Moreover, he's not even human! Long, silver hair frames a face; sharp, majestic devil horns sprout from his head. His form possesses a medieval beauty, capable of being perceived as either male or female, with an enigmatic pattern etched around his eyes. He is a mysterious demon, clad in a purple robe that conceals his entire being. Drawing myself up, I prepare myself.

『...... Oi...... well, I never... child...』

“Heh!?”

『Can you discern my voice? Do you acknowledge my presence?』

“W-What kind of nonsense are you spouting! Wait, how did you gain entry to this room? Are you some kind of demon? A thief!?”

『What!? How could this have happened... surely not..... has something shifted in my fifteen years of solitude?』

Fifteen years? What is this fellow rambling about? No matter how I analyze the situation, he doesn't appear to have a physical form, yet I sense a peculiar aura about him. This individual is far from ordinary!

“Little man... you're being quite loud. Did you actually attempt to draw the sword?”

“Sadiz! Be careful, there's a strange person here!”

“......?”

At that moment, Sadiz, drawn by the commotion, enters carrying cleaning implements. There's no cause for concern here. Despite being a maid, Sadiz graduated from the Academy with exceptional results, earning qualifications as a 【Superior Warrior】. While her contentment with serving as my personal maid remains a mystery, she was once as skilled as my private bodyguard during my childhood. With both Sadiz and myself present, no matter who this entity may be, he stands no chance...

“Little man, there’s no one there...”

“Eh?”

“...... You've remained a virgin for so long that you've finally begun to hallucinate with your delusions... Oh dear...”

I had most certainly perceived the demon within the sealed chamber, but the fact that Sadiz could see nothing left me utterly astonished. “Eh? What, why? He's right there, isn't he?”

“Lil' Earth, please abandon this tactic. Attempting to startle me into initiating intimacy is futile. Therefore, kindly maintain your virginity for a while longer.”

“No, no, it's not like that!!”

“Well, I still have preparations to undertake. Please refrain from making excessive noise, Little Man.”

She genuinely cannot perceive him? Sadiz departs, resuming her cleaning duties.

『...... It appears...... you are the sole individual capable of perceiving me... child...』

“Wha...!?”

『Even so...... When I possessed a corporeal form, I lived for tens of thousands of years, but... it brings me a measure of joy to converse with someone for the first time in over a decade... I am quite frail... under the current circumstances, I would be defeated by humans....』

Is he jesting? Impossible, I'm the only one who can see him?

『Confined within this restricted area... the only disturbance occurs during the annual cleaning... For such an event, what could it signify? A jest by the divine? Well, regardless of the reason... it all pertains to you... my intuition declares. Though I was captivated by this sword, yet... child, you too possess curiosity!』

“What, what…”

『It's rather ironic, but... in a way, a stroke of fortune. I was estranged from the outside world because this sword had remained in this very room since my downfall. Hahahaha!』

“Uh, W-What is this? Hey, what in the world is wrong with you!”

At that moment, the demon drew nearer, his body quivering, a smile contorted with ecstasy and madness adorning his face.

“Stay back! No matter who you are... I know you are listening! You want a thrashing!”

I seized the mop that Sadiz had set aside in anticipation of the cleaning.

Grasping it as if it were a sword, I amplified its power by infusing it with lightning magic, a domain in which I excel.

『Hoh~... 【Magic Sword】... but...... it lacks refinement.... utterly mediocre... a pale imitation of Hiro's mastery.』

“Heh!? Y-You…!”

So engrossed was I that I swung at the demon. Yet, the demon, whom I believed to be struck, inexplicably phased through my attack.

『It is futile. Your assault holds no meaning against a spiritual entity. However, you are the fortunate one, as only a spiritual body remains.』

“What the…!?”

『With a magic sword of this caliber, even if you were to train for a millennium, you would not even be considered a minor adversary during my active period.』

“……Wha. …”

『It matters not; you shall be under my tutelage from this moment forth. I shall bestow my name upon you.』

I felt nauseous as the demon’s gaze met mine.

『I am ‘The Great Demon King Tre’ainar’...... he who once sought dominion over the world, only to be vanquished by your father and his allies.』 [2]

“Huh!?”

『The world of today, which I lost... I shall experience it anew through you, my child.』

And then, awareness deserted me.

[S1] Enter the Great Demon King! I decided to have him use a more sophisticated speech pattern. Light Shakespearean speak (like using “tis” instead of it’s) and more high born vocabulary. So yeah, to the THESAURUS!!!

[S2] Ooooh $%#@! Here we go again! The Great Demon King, the titular “Master” is literally named “Trainer”. So I played around with the name to make it look more foreign!