Somewhere in an underground abyss hundreds of kilometers from Tokyo.
Infinity Castle.
Intricate wooden structures floated upside down, the laws of gravity had ceased to exist here.
A crisp sound of a biwa echoed in the center of the great hall.
Nakime plucked the strings.
Accompanied by the sound of twisting space, several figures exuding terrifying pressure were forcibly teleported into this eerie space.
"Oh my, it's been such a long time, everyone."
A man with long, platinum-blonde hair, his head looking as if it had been splashed with blood, broke the silence with a smile, swaying the golden iron fan in his hand.
His rainbow eyes curved into crescents, and his tone was as light as if he were attending a gathering of old friends.
Upper Rank Two, Doma.
He looked around, then locked his gaze on a pink-haired man nearby, leaning in with feigned intimacy.
"Isn't this Akaza? I heard that when you went on a mission a while ago, you were made to look quite pathetic by a few demon slayers? You even had to escape after losing an arm, it's truly heartbreaking. If you had asked me, I definitely would have helped you eat those humans who bullied you."
Doma's words were filled with hypocritical concern, but to Akaza's ears, they were more piercing than any mockery.
Akaza whipped his head around, undisguised killing intent erupting from his golden pupils.
Recalling the humiliating memory of being "forced back by the Flame Hashira and the lightning swordsman at the cost of their lives," the rage in his heart was instantly ignited by Doma.
Bang!
Without any warning, Akaza's fist struck Doma's face with a sound that tore through the air. The immense force instantly shattered the lower half of Doma's face, scattering flesh and bone fragments.
"Shut your stinking mouth, Doma. If you dare say another word, I'll shatter your head along with it." Akaza warned coldly as he withdrew his fist.
Doma's mangled face quickly regenerated amidst a writhing motion.
Far from being angry, he maintained his smiling expression, covering half his face with his fan. "Oh my, Akaza's temper is still so explosive, even though I was only concerned for you."
"Enough."
A low voice came from the highest pavilion.
The voice was not loud, but it made every Upper Rank present tremble.
A man wearing a purple snake-patterned kimono with a katana at his waist stood quietly in the shadows. He had six eerily arranged eyes, his gaze coldly looking down at the farce below.
Upper Rank One, Kokushibo.
"Akaza, you have overstepped. If you have any dissatisfaction, you may apply for a Blood Battle. Do not commit such an unsightly act here." Kokushibo spoke slowly.
Akaza snorted coldly, ignored Doma, and turned away.
Just then, the sound of the biwa rang out again. All the wooden structures began to shift and rearrange rapidly, eventually piecing together a wide walkway in front of them.
At the end of the walkway, a man wearing a black kimono, his face as pale as paper, stood with his back to them, hands behind his back.
The temperature in the air plummeted to freezing.
The Upper Ranks, who had just been harboring their own thoughts, immediately knelt on one knee in unison upon seeing that figure, bowing their heads deeply.
"Muzan-sama."
Muzan did not turn around. His voice seemed to come from the depths of hell, carrying a suffocating sense of oppression.
"Daki and Gyutaro are dead."
As soon as these words were spoken, the demons kneeling below reacted in different ways.
"Eek! How terrifying! An Upper Rank was actually killed! Will I be next? It's too terrifying!"
An old man with horns on his forehead and a skeletal frame lay on the ground, shaking violently, his tears and snot flowing all over the floor.
This was Upper Rank Four, Hantengu.
Beside him, a deformed monster emerging from a porcelain pot twisted its body in disbelief. "How is that possible? Although Gyutaro had poor taste, his strength was legitimate. How could he be killed by those lowly humans?"
Upper Rank Five, Gyokko.
Doma tapped his forehead with his iron fan, and two tears squeezed out from the corners of his eyes. "Wuwuwu, how pitiful. Those two children were working so hard, who could be so cruel as to kill them?"
"Shut up."
Muzan turned around, his pupils sweeping coldly over the people below.
"One hundred and thirteen years. This is the first time there has been a vacancy among the Upper Ranks of the Twelve Kizuki."
Muzan's tone was filled with extreme dissatisfaction and tyranny. "You trash, have you been living in comfort for too long and forgotten your duties? It's one thing to not find the blue spider lily, but now you can't even clean up those bugs from the Demon Slayer Corps."
All the Upper Ranks dared not even breathe.
Muzan's gaze finally landed on Akaza. "Akaza, combined with the information you brought back last time, those Hashira of the Demon Slayer Corps seem to have mastered a technique that can briefly overdraw their vitality to increase their combat power."
The technique Muzan spoke of naturally referred to the "Demon Slayer Mark" that had appeared on Kyojuro's face, which he had seen in Akaza's memory that had been tampered with by Yamada.
In Muzan's logic, although Gyutaro was not weak, he was definitely not considered top-tier.
Since the Flame Hashira could unleash that kind of power, if the Demon Slayer Corps sent two or three Hashira to work together, coupled with that life-overdrawing fighting style, it was indeed possible to wear down the careless Gyutaro and his sister.
He would never have imagined that the one who had killed Upper Rank Six was a monster who didn't even need to draw a nichirin blade, and who casually reduced Gyutaro to ashes with black flames.
(Amaterasu burned them too thoroughly, so Muzan could not read the memories of Gyutaro and Daki before they died through their cells.)
Yamada's strategy of playing the long game to catch a big fish worked perfectly on this suspicious and arrogant Demon King.
'Demon Slayer Mark... that accursed thing has actually appeared again.'
A trace of imperceptible gloom flashed in the depths of Muzan's eyes. It was the psychological trauma left by Yoriichi hundreds of years ago.
He could not tolerate the existence of any variable that could threaten his life. Even if it was just a tiny spark, it had to be completely extinguished.
"Since the demon slayers have started to group up, there's no need for you to hunt for prey alone anymore."
Muzan took a step forward and began to issue new orders.
"Gyokko, you mentioned earlier that you had gathered clues regarding the Demon Slayer Corps' Swordsmith Village?"
Hearing Muzan call his name, Gyokko, who had emerged from his pot, immediately rubbed his hands excitedly, his misplaced facial features twisting into a fawning smile.
"Yes, Muzan-sama. My pot detected a hidden valley. Although it hasn't been fully confirmed, there is the scent of a large amount of high-quality ore there. I am 90% sure that it's the nest where those demon slayers forge their swords."
"Very well."
Muzan ordered coldly: "Hantengu, you go with Gyokko. After confirming the location, raze that village to the ground. Kill all the swordsmiths. Without their nichirin blades, those demon slayers will be like dogs with their teeth pulled, left to be slaughtered by us."
"Understood. Muzan-sama." Gyokko accepted the order excitedly.
Hantengu trembled while kowtowing. "Yes... yes... I will definitely do as you say..."