It was a moment of catastrophe for humanity.
In the plains of Waterlull, interwoven with swamps, the Leaf Empire’s army successfully encircled the demon forces with an overwhelming force of 30,000 soldiers.
At that time, the number of demons trapped within the encirclement was a mere 7,000—less than a third of the Imperial Army’s strength.
Given these odds, the Imperial forces were certain of their victory.
However…
That certainty turned into despair in an instant.
The heads of shield-bearing soldiers were sent flying.
Spear-wielding warriors collapsed, spewing blood with agonized screams.
Wasn’t it supposed to be different?
No… This isn’t right!
A tightly woven siege line began to crumble in mere moments.
Amidst the chaos and the wailing cries of dying soldiers, the truth dawned upon them far too late.
They hadn’t encircled their enemies.
They had only walked into a trap.
Like a crimson tide of death surging through the battlefield, devastation spread without mercy.
And at its very center.
She stood.
Demon General Flantsu.
Those who later recalled the scene described it as follows:
“A monster, orchestrating a symphony of slaughter with laughter as her instrument.”
With every echo of her laughter, soldiers fell, unable to resist—merely dying, one after another.
Blood flowed like a river across the ground, while desperate screams of terror echoed from all directions.
After carrying out such a horrifying massacre, Demon General Flantsu and her soldiers leisurely slipped away from the shattered siege.
This nightmarish defeat left a deep scar on the Empire.
From that day forward, they gave her a name.
The Calamity of Waterlull.
And now.
That very “calamity” stood before Mari.
Smiling in pure delight.
Rubbing her chest against Kesar’s arm with eager affection.
“Should I be impressed by the Demon Lord instead?”
Mari couldn’t be sure of many things, but one fact was clear—
To humans, Flantsu was a walking nightmare.
Yet in front of Kesar, she transformed into nothing more than a docile puppy.
“Judging by her behavior… she must have had feelings for him for quite some time.”
If she was willing to display such blatant affection in front of others, it meant she was more than accustomed to this.
And for Mari, this situation was… uncomfortable, to say the least.
“…Huh?”
A tight, suffocating sensation gripped her chest.
It made her wonder.
“Why…? Why does watching this scene make me feel so irritated?”
Mari had never been one to concern herself with others’ romantic affairs.
Once, long ago, she had held feelings for a man.
But that was a one-sided affection, something she had long since abandoned.
After that, she had no interest in love—especially not in anyone else’s.
And yet.
This moment.
This sight before her.
The way that woman clung to Kesar.
It stirred an unexplainable irritation within Mari.
As if a needle had pierced her heart.
A tingling, almost unbearable emotion welled up inside her.
Of course, there was nothing she could do about it.
All Mari could do was silently watch this uncomfortable scene unfold before her.
Irritated and confused by this inexplicable discomfort, she wordlessly followed behind the affectionate pair, heading toward the Demon King’s Castle.
At that moment.
She remained unaware of the gaze fixed upon her.
It had been a while since she last returned home.
If it were up to her, she would have thrown herself onto the bed the moment she arrived.
But before that, there were things she had to take care of.
“Ugh…”
During the past few months she had been away, a mountain of work had piled up in her absence.
Most of the internal affairs had been handled by Flantsu, but there were still many matters that only she could resolve.
For the time being, she had no choice but to devote herself entirely to work.
Times like this always made her think.
“I just want to retire and live a peaceful life as soon as possible.”
Unfortunately, such a future was never an option for her.
Knowing too much was a crime in itself.
If she stepped away now, the consequences were obvious.
And in that process, there was a 100% chance her head would roll.
Caught in the inescapable cycle of duty, Mari had no choice but to continue stamping away at the endless stack of documents.
And then.
“Here you go, Lord Kesar~ You should have some while you work.”
“Thanks.”
Flantsu handed him a freshly brewed cup of tea.
At this moment, she was the one most openly and confidently displaying affection toward him.
And honestly.
Her boldness was more than a little overwhelming.
“It’s better than being on bad terms… but still, isn’t this a bit too much?”
Originally, Flantsu was supposed to be sitting in the very seat I’m in now.
In other words.
She was meant to be one of the Four Great Demon Lords in the original story.
And in the game, her combat strength was practically unrivaled, making her the strongest among the Four Great Demon Lords.
The lore might have claimed that she was slightly weaker than the other Demon Lords, but from a player’s perspective, that was complete nonsense.
While the other Demon Lords were defeated within a week of being released, Flantsu alone held her ground for over a month.
At first, she was so unbeatable that forums were flooded with complaints: “Did they really make this for humans to clear?”
Eventually, some of her attack patterns were patched, and even then, she wasn’t cleared until almost two weeks after the adjustments were made.
Flantsu was a monstrous boss whose lore and actual in-game mechanics didn’t align at all.
Knowing this, I figured it was only a matter of time before she became overwhelmingly powerful, even if she wasn’t quite there yet.
That’s why I intentionally showed her kindness here and there.
I would praise her a little more than others.
I’d share tea with her while working.
Appointing her as my assistant, where she could shine in administrative matters, was also part of this plan.
The problem was that this kindness seemed to have had an overly strong effect.
At some point, she began openly expressing her affection toward me without any hesitation.
In the original story, she had the vibe of a cold, villainous lieutenant through and through.
Seeing this unexpected side of her now was something I never anticipated.
Of course, having intentionally shown her kindness, it felt wrong to reject her affection outright.
“At least she hasn’t crossed the line yet…”
Given the circumstances, I used the demons’ cultural emphasis on chastity to maintain a clear boundary.
The problem, however, was that she only just barely respected that boundary.
Even now.
“Ah, I’ve already taken care of that matter. I installed a drainage system, so you won’t have to worry about any flooding~♥”
“O-oh, r-right. Is that so?”
“Yes, I installed them right… here…”
With those words, Flantsu leaned forward, smoothly pressing her chest against my shoulder.
The sudden, dizzying fragrance that accompanied the motion made my head feel light for a moment…
“Here… and here… and hehehe, right here.”
Each time she pointed at a spot on the map, she deliberately pressed her chest down against my shoulder.
Her sultry voice left no doubt—she was intentionally seducing me.
But I endured it.
“Sorry to disappoint, but I refuse to give in to lust in a situation like this.”
I knew all too well how dangerous it was to let these things spiral out of control.
With a mountain of work ahead of me, there was no time to get distracted by a woman— especially if it led to… complications.
If she ended up pregnant, when I was already stretched thin handling everything as it was…
“Losing a key military asset for an entire year? That would be a disaster.”
Considering the upcoming chain of events, I had to resist.
“That’s it for today. You’re dismissed. I need some rest as well.”
“Hmph… Alright, understood.”
And so, in today’s battle between reason and instinct.
Reason won.
Flantsu, though slightly pouting, accepted my order to leave.
Though I couldn’t deny…
A small part of me felt a bit disappointed, too.
“Still… those breasts are always top-tier, no doubt about that…”
A moderately spacious room.
Mari carefully scanned her surroundings, taking in every detail.
It was a private chamber within the Demon King’s Castle, personally assigned to her by Kesar.
Fully furnished, neatly arranged a clean and organized space.
As she explored what would now be her living quarters,
she couldn’t help but notice the thoughtfulness behind it.
A quiet smile formed on Mari’s lips.
At that moment.
“You look rather pleased with yourself, human.”
A sudden, cold voice cut through the silence.
At the same time, an ominous presence sent chills down Mari’s spine, making her swiftly turn her head.
“…You are…?”
“Flantsu Napolita. You’ve heard my name before, haven’t you?”
…
Flantsu spoke with a tone so filled with murderous intent that it was suffocating.
Gone was the lively, overly affectionate demeanor from earlier.
Now, she radiated nothing but pure, chilling hostility.
A bloodthirst so intense, it felt like she could tear Mari apart at any moment.
Feeling the overwhelming tension, Mari instinctively glanced at the staff she had left nearby.