Became the Emperor of the Demon Realm Empire
Chapter 1: 300 Years Have Passed since the Prologue
To cut to the chase, I was reincarnated into a NTR hero story.
What exactly the story was about and why I was reincarnated into it isn’t particularly important.
Digging up memories from a past life that ended 300 years ago would only make me feel more troubled.
Still, if I had to recall, I think I saw a truck in my final moments.
I don’t know why I died.
I distinctly remember dodging the oncoming truck with a nimble sidestep.
“Ah.”
Now that I think about it, I didn’t die from being hit by the truck.
I fell into an open manhole and saw a spiritual light as I tumbled down.
“What a pathetic way to die.”
When I opened my eyes again, I was the 72nd ranked Demon Lord, Alteron, the lowest-ranking ruler in the demon realm.
For a brief moment, I wondered why I had been reincarnated as a demon king instead of the NTR hero.
But first, I had to figure out how to survive.
From the very beginning, my dungeon was on the verge of bankruptcy, plastered with red foreclosure notices by the Dungeon Merchant Guild.
There was no rule saying I had to just lie down and die.
I took out a loan from the guild, using my soul as collateral, and fortified my dungeon’s defenses.
Surprisingly, the adventurers were so weak that my dungeon never fell.
However, the Dungeon Merchant Guild was a dark organization collecting the souls of demon lords to dominate the demon realm.
Other demon lords were certain I wouldn’t last long and would soon vanish.
So, my decision to borrow money from the guild stirred hostility across the entire demon realm.
They said if I was going to die, I should’ve just died quietly, why pledge my soul to the guild and make them stronger?
But those sneers and taunts didn’t last long.
Within seven years, I repaid every last coin I owed the guild.
With a stroke of luck, I recruited a Skeleton Knight and expanded my influence.
By the time I had grown somewhat stronger, I had climbed to the 66th rank in the hierarchy.
Yet, that was also the moment my greatest enemy shifted from humans to demons.
Demon Lords who took an interest in me began threatening me to join their factions.
The Dungeon Merchant Guild, which kept the demon lords in check, tried to lure me in with all sorts of sweet promises.
The threat that grew as I grew rapidly spurred me on even more, and it was probably around that time that I began to borrow knowledge from the original work.
Freeing Jormungand from the bio-experimentation lab.
Releasing the True Dragon and the Succubus sealed by the Holy Church.
Kidnapping the future Beast Lord, who was persecuted by his own kind.
Thus, with the four demons who would later be known as the Four Calamities, along with my Skeleton Knight, I systematically purged the demon lords one by one.
The Dungeon Merchant Guild was no exception.
I was the only one who abandoned my dungeon, rebelling against the existing dungeon system.
Stuffing my growing forces into a dungeon was suicidal, and since the dungeon system held no real value for my goal of conquering the demon realm, it was something I had to do eventually.
Naturally, conservative demons fiercely opposed this.
But the demon realm had always been a place where the strong ruled.
The strong were always right, and those who opposed my ideology were simply swept away.
Even the highest-ranking Demon Lord, the greatest threat of all, met his end that way.
“Congratulations, Your Majesty.”
And so, 300 years later, on this very day.
I became the first emperor to unify the Demon realm.
The name of the nation: the Empire.
The Dungeon Merchant Guild, having long since surrendered, was reorganized into an engineering division under the Demon Lord’s Army and scattered across the land.
The legions of the Empire, voraciously absorbing defeated soldiers and defectors, stood ready to die at my command at any moment.
“There are no more forces left to oppose me.”
It took a long time to find the answer, but.
The hell I had been struggling through was not the afterlife after all.
──Now, it’s truly over.
“To think that pathetic older brother of mine is now the emperor of the Demon realm! Ugh…! This little brother is so moved he could cry…”
“Hey, I don’t think Endymion can shed tears because he’s a skeleton…….”
“Your Majesty. Tonight, I, your empress, shall attend to you. Do you prefer black or red lingerie?”
“Trashy wench.”
“…What?”
“If anyone could just declare themselves empress, what would be the point? Honestly, women like you who only think about nighttime activities have nothing in their heads. Frankly, do you even know what an empress is?”
Suddenly, the True Dragon and the Succubus glared at each other.
It would’ve been nice if someone had intervened on such a fine day, but the timid Echidna hesitated to step forward in front of others, too afraid to mediate.
TAP!, TAP, TAP!
Even the relatively sane Skeleton Knight just clicked his jaw in amusement, enjoying the spectacle…
“……”
“Why are you looking at me with such pitiful eyes?”
I wasn’t particularly disappointed.
Disappointment is an emotion that only comes when you have expectations.
“An empress should be a woman of both integrity and refinement. It’s not a position for a stupid pink-haired woman like you to covet.”
“What’s wrong with my hair color? Sis, that’s just prejudice.”
“It’s not prejudice—it’s statistics, little sister.”
“Ugh, so annoying.”
“Hehe, looks like I won this argument?”
“Yeah, yeah, flat-chest.”
“Oh? Run out of things to say already?”
“Flat-chest.”
“I shouldn’t expect anything from an idiot like you.”
“Flat-chest.”
“……”
“Washboard?”
“I’ll kill you.”
“Did you hear that, Your Majesty? Sis’s chest is as flat as chewing gum!”
The Succubus, Sitri, fluttered her wings and circled around, while Cecilia clutched her teddy bear tightly.
“Watch your tongue.”
The vertically slit pupils burned red.
As expected of a True Dragon who had lived a thousand years, Cecilia’s sheer killing intent was enough to weigh down my lungs.
“Enough.”
“……”
“This gathering was meant to discuss the future of the Empire. Refrain from idle chatter.”
That was the truth.
The reason I had summoned my closest aides, the very individuals who had helped unify the Empire, was because the decision at hand was of grave importance.
“Even after unifying the demon realm, our enemy remains.”
The question was, could the Empire invade humanity?
Four of the five Grand Dukes who ruled the demon realm had gathered for this very state council.
Cecilia was the first to speak.
“Your Majesty. Humanity deserves annihilation, but it is also true that we must limit our movements until order is fully restored in the demon realm. For the next 30 years, we must focus on stabilizing internal affairs.”
Though I didn’t show it, I fully agreed with Cecilia’s opinion.
Demon Lords could command legions through a unique psychic network known as the Hive Mind, but this command structure had a fatal flaw.
Reclusive hardliners could still hear my voice.
This was a side effect of my overwhelming presence spreading across the demon realm after so much infighting.
They were high-ranking demons capable of resisting mental domination—and they still opposed my ideology.
If we made contact with humanity and our march was leaked, we would have to brace for significant losses.
“Your Majesty, don’t listen to Flat-Chest’s advice.”
Then, Sitri suddenly cut in.
For a moment, Cecilia seemed to bristle, but I assumed it was just my imagination. After all, adults should know how to be gracious sometimes.
“Humanity can be crushed under the sheer firepower of our legions. Humans are still too busy fighting among themselves, they could never stand against the Demon Empire.”
Sitri argued that there was no reason to hesitate against such a disorganized rabble.
“Impressive…”
Honestly, I was a little surprised. I hadn’t expected her to recite her entire argument without stumbling over notes.
I guess being called stupid had motivated her to practice.
“This is so absurd it’s giving me anemia. Now I see why Your Majesty never ordered you to join the war.”
“Don’t ignore me. Remember how we took down Cat King Nato’s dungeon? I was the one who seduced that undead to win!”
That really was commendable.
Even I had to rub my eyes in disbelief when the Cat King’s cheeks flushed red.
The expression on his face after Sitri betrayed him was something I still couldn’t forget even decades later.
That guy… was secretly a romantic.
“…Do the two of you have any opinions?”
I turned my gaze to the two who had remained silent.
Echidna fidgeted under the pressure, while the Skeleton Knight just shrugged.
“I don’t particularly want to harm humans, but it’s not like I have a choice, right? Do as you please, boss.”
“I-I’ll also follow Your Majesty’s will…”
As their voices trailed off, silence fell. This was a question I had struggled with for decades, and my thoughts grew heavier.
“If coexistence with humanity is impossible, then eliminating them is the right choice.”
While demon ideology could be resolved through brainwashing, humans were different.
Their hatred for demons wouldn’t just disappear with a handshake.
“This is tough.”
My hesitation wasn’t because I was once human.
Every political decision has side effects, and even wise judgments are no exception.
Above all else.
Something felt off.
Like I had forgotten something important…
“Wasn’t this the future we foresaw? The annihilation of humanity has always been the demon race’s wish. If we have the power to crush them, hesitating is just stupid!”
“Pfft.”
“…Why are you laughing?”
Sitri narrowed her eyes at Cecilia’s sneer.
That woman always made that face whenever someone called her stupid.
“Your Majesty, the timing isn’t right for an invasion. Can we really trust the half-baked ideas coming from that idiot’s head?”
“Hmph. Whatever.”
“Last night, a hero was born in the human kingdom.”
“…What?”
The room erupted into chaos.
For a moment, I doubted my ears.
“Your Majesty. The last time a hero appeared was 300 years ago. Since the goddess hasn’t exercised her power since then, this generation’s hero will likely surpass all common sense.”
Cecilia paused briefly before continuing.
“Of course, I’m sure Your Majesty was already aware of all this.”
All eyes turned to me.
Even Endymion , the most passive in state affairs, had fire in hiseyes.
“Brother, is the old hag telling the truth?”
“Endymion , I told you not to call me an old hag—”
“Brother! Answer me!”
“……”
I said nothing.
No—I couldn’t.
Suddenly, my mind and body felt exhausted, and my breathing grew ragged, as if my lungs had been taken hostage.
“Your Majesty…?”
I realized why I had felt so uneasy.
Why I had hesitated to invade humanity.
Why I had thought my true enemy was the demons.
I had finally remembered something crucial, something I had forgotten all this time.
“Today’s council is adjourned.”
“Y-Your Majesty…?”
I rose from the throne and walked out.
A hero appearing after 300 years this was part of the original setting of the ‘NTR Hero’ story I had been reincarnated into.
……In that era’s story,
……the Demon Lord was always slain.
“Should I retire?”
On the very first day of my reign as emperor, I found myself yearning for retirement.
