A vast and immeasurable power surged out from Muzan, spreading like a shockwave from the center of the Infinity Castle. As the Demon King, his will was absolute, and a mysterious energy pulsed through the impossible architecture, reaching out to every corner of the world. From the most powerful of the Twelve Kizuki to the weakest demons hiding in the shadows, every creature born of his blood felt the summons at the exact same moment.
An indescribable fear bloomed in their hearts, a cold and primal instinct that they were powerless to resist.
"It's... it's a summons from Lord Muzan!" one whispered in a dark alley.
"Something big must be happening," another hissed as it abandoned its hunt.
Instantly, the thirteen most powerful demons who served directly under Muzan Kibutsuji felt the pull. No matter what they were doing or where they were, they vanished. The moment Muzan's will was sent out, the moment the sound of Nakime's biwa echoed in their minds, their previous reality ceased to exist.
When they opened their eyes again, they were kneeling in the Infinity Castle. Before them, standing on a high platform, was the arrogant and powerful figure of their master.
Thump.
Thump.
Thump.
Without a single moment of hesitation, the six Lower Ranks of the Twelve Kizuki slammed their foreheads to the ground. Their eyes were wide with a terror that went beyond simple fear. In the outside world, they were lords of the night, arrogant and cruel beings who held the power of life and death over humans. But here, before Muzan, they were nothing more than ants that he could crush at any second. After all, their powers, their strength, and their very lives were gifts from the man who now stood before them.
"Lord Muzan!" they all cried out in unison, their voices trembling.
At the same time, the seven Upper Ranks of the Twelve Kizuki looked up at the man on the platform with the deepest respect and reverence. They, too, owed him everything. Without him, they would have died centuries ago, their bodies rotting in the ground. But because of him, they possessed terrifying power beyond human comprehension and a life that was nearly eternal. Aside from their inability to walk in the daylight, they lived as gods among men.
Because of this, their feelings for Muzan were less about fear and more about absolute, unwavering loyalty. They understood that even as the mighty Upper Ranks, their every thought and action were still under his complete control.
"Lord Muzan," a calm, deep voice said.
Among the Upper Ranks, a man with six eyes, dressed in the formal samurai attire of the Sengoku period, spoke with perfect respect. He gave a low, meticulous bow, his movements showing the strict etiquette of a warrior.
This was Kokushibo, Upper Rank One of the Twelve Kizuki.
He had another name, one from his human life: Michikatsu Tsugikuni. He was the elder brother of Yoriichi Tsugikuni, the legendary genius swordsman who created the first Breathing Style. But any connection to that past was long gone. After turning into a demon, he had eventually killed his own frail, elderly brother. Now, the only being he recognized as his superior was Muzan Kibutsuji.
To Kokushibo, fleeting things like beliefs, emotions, and willpower were meaningless. Eternal life and limitless power were the only things that held true value. It was for this reason that he had abandoned everything—his family, his humanity, and even his samurai pride—to willingly become Muzan's servant.
"Good," Muzan's voice echoed from the high platform, acknowledging his strongest subordinate.
Meanwhile, at the Ubuyashiki family estate, a change was also felt.
Kagaya Ubuyashiki, the head of the Demon Slayer Corps, had been lying in his bed. A terrible curse, passed down through his family for generations, was slowly eating away at his body. He was in a coma for most of the day, with only brief moments of consciousness. But just now, his eyes snapped open, and a look of horror spread across his disfigured face.
His family had been cursed a thousand years ago because of Muzan Kibutsuji. But with that curse came a strange gift: the head of the Ubuyashiki family always possessed a powerful intuition, an ability that was almost like seeing the future.
What's happening?
Kagaya's mind felt as if it had been struck by lightning. "Just now, I felt a strange but familiar power... It was Kibutsuji Muzan!"
For centuries, his family had carried the burden of fighting demons, creating the Demon Slayer Corps to protect humanity. After a hundred years of work, they had finally assembled the current generation of Hashira, the strongest group of demon slayers in history. It was a golden age for the Corps. Kagaya believed that if they had any chance of finally killing Muzan, it was now. This hope was the only thing that kept him fighting against the curse that was destroying him.
But the feeling he'd just had was wrong. It was different. He could clearly sense that a change he couldn't possibly understand had just occurred. And the source of that change was the very demon he had dedicated his life to destroying.
"The future..." he whispered, his voice weak. "What is going to happen to the future?"
For the first time, even with his keen intuition, Kagaya Ubuyashiki could not see what was coming.
At the same time, in a quiet house in Asakusa, Tokyo, another felt the change.
Lady Tamayo had just finished her medical experiments for the night and was about to rest. Suddenly, her heart began to pound in her chest, and a terrifying cold washed over her body. In that instant, she was transported back in time, back to the night she was tricked by a demon, the night that led to the greatest tragedy of her life. It was a nightmare she could never forget, the memory of how she became what she was now.
And that feeling, Muzan's presence, was back.
"Lady Tamayo, what's wrong!?" Yushiro, who was standing guard nearby, rushed to her side, his own heart filled with fear. He was a demon she had created, saving him from a fatal disease, and his devotion to her was absolute.
"That demon... that demon..." Tamayo whispered, her body trembling.
Yushiro stared, horrified. In his eyes, Lady Tamayo was a perfect, unshakable woman. He had never, in all his years with her, seen her look so terrified. It was as if she were staring at a ghost from her worst nightmare.
Back in the Infinity Castle, Muzan looked down at the Twelve Kizuki. They were all kneeling before him, completely respectful, as if they were worshiping a god. His ruby-red eyes held no emotion, neither joy nor sadness.
"I have summoned you here for two reasons," he announced, his voice carrying across the silent space. "First, we will destroy the Demon Slayer Corps. And second... I intend to take control of this entire country of Japan."
A ripple of shock went through the assembled demons. Muzan projected images into their minds—scenes of conquest, of cities burning, of a world ruled by demons under his command.
Even though they were powerful, immortal beings, the hearts of the Twelve Kizuki began to race. They could not believe what they were hearing. Their master, who had always hidden in the shadows and moved only at night, was now planning to conquer the entire nation.
Was he going to turn the current Taisho era into an age of demons, a world made exclusively for him?
For the first time in a very long time, a strange new emotion filled the hearts of the Twelve Kizuki: a mix of terror and exhilarating excitement.