In the deep, dark, and damp cave. The acrid scent of earth and mold permeated the air.
For one who was once the master of the Infinity Castle, a fortress that defied all physical laws, this place was pitifully shabby and wretched.
Kibutsuji Muzan leaned against the wall, breathing heavily. His bloodshot eyes wavered uneasily.
"This is impossible... It can't be happening..."
His nails scraped against the rock, producing an eerie sound.
Not long ago, he had doubted his senses. His connection with Upper Moon Four, Nakime, had been severed.
It wasn't just that she had died. Her very existence had been usurped by someone.
And at that moment, his control over the Infinity Castle was completely lost.
The castle, formed from the Blood Demon Art of a subordinate he had created, the infinite space that had long been his possession, had been wholly taken over by another.
"How dare... how dare they take my castle...! My space!"
Muzan was furious. This was not merely losing a hideout.
It was the violation of his absolute authority and safe haven, built over a thousand years, by an unknown enemy.
He hurriedly tried to summon the remaining Upper Moons.
But only a few responded. Hantengu's presence had vanished as well. Even Kokushibo, the strongest sword he trusted most, was out of contact.
"Kokushibo... you too...! Have you been defeated? Or... have you betrayed me?"
The moment the word "betrayal" left his lips, a chill ran down Muzan's spine.
Kokushibo couldn't have betrayed him. He was bound by his inferiority complex toward Yoriichi.
Then... does that mean even Kokushibo has been subdued?
In this world, the only ones who could defeat him were Muzan himself and Yoriichi, who died centuries ago?
Muzan began to bite his nails. Anxiety and unease gnawed at his reason.
He didn't even know who the enemy was. The Demon Slayer Corps? No. Those insects don't have such power.
They were organized, possessed overwhelming force, and, above all, understood and exploited the power of demons.
The woman in the red cloak who killed Akaza. Reports of an Upper Moon being eliminated with something like a matchlock gun.
And the man in black who dominated Nakime and stole the Infinity Castle.
"Who are you... what is your true identity..."
A nightmare from centuries ago surfaced in Muzan's mind. The swordsman with hanafuda earrings, Tsugikuni Yoriichi. The fear and helplessness, as if his soul were burning, when he was cut by him.
The emotion he felt now was similar to back then.
No, perhaps it was more insidious and despairing. Yoriichi was just an overwhelming individual like a natural disaster, but this enemy was an organization.
Hunters who thoroughly analyzed him, hunted him, and stripped away everything he had, one by one.
The clue to the mysterious deaths of the Upper Moons over the past few years had finally been grasped.
"I... am I being hunted?"
He, the progenitor of demons, the ruler of the night. It was an intolerable humiliation. But his body honestly reacted with fear.
Muzan struggled to regain his composure. He couldn't just rage.
He had to survive. Survive and repay this humiliation without fail.
He looked down at the Lower Moon demons cowering at his feet, trembling violently, and the new Upper Moons hastily filling the vacant positions.
'Useless things...'
Powerful ones like Kokushibo, Akaza, Hantengu, and Nakime were all gone. What remained were mere small fry. With them, they couldn't oppose the unknown enemy.
"Listen."
Muzan's voice lowered, filling the cave.
"From this moment on, all operational policies are changed."
His eyes flashed coldly.
"First, the search for the Blue Spider Lily is temporarily suspended."
A stir could be felt among the demons. Suspending a thousand-year-long aspiration. It meant the situation was that serious.
"Right now, surviving this night takes precedence over overcoming the sun."
Muzan clenched his fist. He didn't want to admit it, but he had to.
It was wartime. And he was overwhelmingly at a disadvantage.
"Second, avoid full-scale battles with the Demon Slayer Corps. Especially... do not make contact with the mysterious force under any circumstances. If you see them, flee immediately. I don't even permit gathering information on them. They are not opponents you can handle at your level."
This was practically a declaration of defeat.
But for Muzan, survival was more important than pride.
"Third, all of you must go deep into hiding within human society. Thoroughly conceal that you are demons, and live like humans. Don't make a sound, not even a whisper, and stay like shadows."
Muzan shuddered with humiliation. In a world where he was the center, he had to hide and live like a rat.
"Remember. Our goal is one and only. Survival."
Muzan muttered as if hypnotizing himself.
"I will not die. I am an eternal, immortal being. No matter who they are, they are merely humans who will grow old and die someday."
Time was on his side. He had to believe that.
"Whether it takes a thousand years, or two thousand... I will wait. Until they let their guard down. Until their true identity is revealed. Until they grow old, fall ill, and die..."
Muzan hid his body in the darkness. The king who had lost his safest castle now descended to the deepest, darkest bottom and held his breath.
Awaiting the day of revenge that would come again someday.
But deep in his heart, a primal fear, felt for the first time since encountering Yoriichi, coiled tightly.
'Are they... really ordinary humans?'
The unanswerable question kept the ruler of the eternal night from sleeping.
Meanwhile, at that time.
Infinity Castle.
In the most secret room of the Infinity Castle, managed by Nakime.
There, Akira was roughly pushing a woman. Black hair like ink, seductively glowing red eyes, and an overwhelming aura—a peerless beauty.
That appearance was undoubtedly the female form that the demon progenitor Kibutsuji Muzan sometimes took.
She let out a sharp gasp. "Master... I, I'm sorry..." Then choked.
But the voice that burst from her mouth was not that of a dignified ruler, but the scream of a low-level demon of this castle, terrified.
"Oh, Akira-san? What are you doing?"
Shinobu, who had entered the room, was momentarily speechless at the bizarre scene unfolding before her eyes.
Akira was violating Muzan, and in female form at that. Akira shot into her mouth.
"Ah, Shinobu. The timing is a bit awkward."
Akira only turned his head to look at Shinobu. Beneath him, the female Muzan, tears streaming and white fluid dripping, trembled with an expression mixed with pleasure and fear.
"Is that... perhaps the real Muzan? No, the presence feels familiar."
At Shinobu's sharp observation, Akira chuckled and moved his hips.
"You noticed, huh? Yeah, it's just the shell of Muzan; the contents are Mukago."
At Akira's words, Shinobu finally understood. She hadn't sensed Muzan's characteristic arrogant and disgusting aura.
"Why such a thing? Your hobbies are quite vile, Master."
"It's not my hobby. It's because of that Nobunaga guy."
Akira paused for a moment and sighed.
"He said this: Female Muzan is honestly one of the top beauties, so why not consider violating her for revenge?"
"Huh? Nobunaga-san is really... mischievous."
"So I answered: I acknowledge the appearance, but with such trash inside, just touching it would make me vomit. Then he suggested: Then how about violating someone else who looks the same? A kind of proxy satisfaction and sense of conquest."
Akira tapped the buttocks of Mukago (in Muzan's form) beneath him.
"I thought it was a stupid idea, but I wanted to try it once, so I manipulated cells to change Mukago's appearance. I analyzed Muzan's blood and remembered the cells, so the body is temporarily identical to Muzan's, inside and out. Well... thinking that it's Mukago inside, it did get me going."
Shinobu crossed her arms and looked down at the scene. Objectively, female Muzan was beautiful.
But for her, that face itself was a trauma trigger.
"She is certainly beautiful. But... the demon that killed our parents was ultimately created by that bastard with that face. Just seeing that face makes me sick to my stomach."
Shinobu's eyes turned cold. Instead of her usual gentle smile, a sinister and cruel smile played on her lips.
"Hey, Akira-san. I just had a brilliant idea."
"What are you scheming now? I always get uneasy when you make that expression."
"Fufu, listen. When we capture the real Muzan later..."
Shinobu approached Akira and whispered softly into his ear.
"We strip him of all his power, render him helpless, and force him into female form. Then make him your sex slave."
"..."
"Not just violating him. We plant false hope that if he pleases me, we'll spare his life. With his abnormal attachment to life, wouldn't he accept even the most humiliating and disgraceful acts, like licking your toes?"
Shinobu's voice gradually rose. A sadistic madness flashed in her purple eyes.
"Then thoroughly violate and break his body and mind... and at the last moment, kill him. Then Muzan will be in despair until the moment he dies, crying out: You promised to spare me! Liar! This can't be happening!—and watch him die ugly. How about it? Isn't it thrilling?"
Akira stared at Shinobu with a dumbfounded expression. Even Mukago beneath him trembled in fear at Shinobu's killing intent, unable to scream.
"Sigh..."
Akira let out a deep sigh and held his forehead.
"You, what's in your head? No, where did the pure, venomous girl I first met go, and why have you become so lewd and cruel?"
"Oh my, you all made me this way, didn't you?"
At Akira's reproach, Shinobu puffed her cheeks and made a sulky face.
"Then... how about changing my appearance to that female Muzan and playing out being violated by you, Master?"
"What?"
"I'd rather die than take on the enemy's form... but if you think of me as Muzan and handle me roughly with hatred... that might be exciting in its own way. Think of it as a rehearsal for the plan I just mentioned..."
Shinobu looked at Akira with a seductive gaze, licking her lips with her tongue. A chill ran down Akira's spine at that sight.
"Please... let's not do that. I beg you. Take care of my mental health."
Akira barely held onto his sanity and shook his head. His harem was growing more extreme by the day, straying beyond the bounds of common sense.
No, perhaps because they shared love daily, they desired rougher, more dopamine-filled, stimulating acts.
Meanwhile...
"Um, I actually like this form. Having the appearance of that vicious former superior and being violated by you, Master, gives me a sense of transgression, I guess. It feels like I've become Muzan, kind of superior, hehe."
"You're not normal either, Mukago."
"Can I stay like this for a few more days!? You can violate me as much as you want! It hurts, but it feels so good!"
"Why are there no normal women here? Do as you like. Since you've received more of my blood, you can probably change your appearance as you wish now. But if you get beaten up while walking around like that, it's your own fault."
"Aww~ You wouldn't do that, would you?"
Afterward, when his relationship with Akira ended.
Mukago, in female Muzan's form, happily wandered around and suffered the humiliation of having her neck sliced by Kokushibo.
She didn't die, but Moon Breathing确实 hurt, they say.
And she was also beaten by Zohakuten, among others. It seemed Muzan was more of a black company president disliked by his subordinates than expected.
Later, when Mukago went to complain to Nakime, as an extra, she was crushed under a house in the Infinity Castle with the sound of a biwa.
But since she liked this appearance more than her original form, she got used to being hit and continued to wander around in female Muzan's form, they say.