Kokushibo lowered his gaze slightly, his six eyes calm yet observant as he spoke in a measured tone. "What troubles you, my lord?"
Muzan Kibutsuji smiled faintly and shook his head, his expression as unreadable as ever. "Nothing of consequence."
Yet the truth lingered beneath the surface.
Everything was because of him.
Muzan's intention was clear he wanted to reassert control. Slowly, deliberately, he extended his hand, expecting obedience. Kokushibo, without hesitation, reached out and grasped it.
For a brief moment, silence filled the Infinity Castle.
…
Then Kokushibo withdrew, bowing slightly. "My apologies, my lord. It was merely instinct."
Behind that composed exterior, however, he was suppressing a surge of dark amusement. The certainty was absolute Muzan would not act rashly against him.
Even if conflict broke out between them, the consequences would be catastrophic. The first casualty would be this very dimension the Infinity Castle, the core of Muzan's concealment and control. It was both fortress and lifeline.
And Muzan would never willingly destroy it.
Regaining his composure, Muzan spoke again, his tone smooth but laced with intent. "Kokushibo, I will grant you more of my blood. Grow stronger."
On the surface, it sounded like a reward.
In truth, it was another attempt at domination.
Kokushibo remained unshaken. Tamayo's medicine had already severed Muzan's direct influence for the time being. No curse, no forced obedience at least not for now.
Still, appearances had to be maintained.
"My lord," Kokushibo replied respectfully, "true strength must be cultivated through discipline. Power gained too easily often lacks stability."
Those words, though calmly spoken, struck Muzan like poison.
Without further discussion, Muzan sliced open his arm. Dark blood flowed freely, rich with demonic essence. "Take it."
Kokushibo did not hesitate. He cupped both hands and caught the blood, consuming it in full.
The result was immediate.
Power surged through his body denser, sharper, more refined than before.
Yet there was no chain.
No suppression.
No command embedded within it.
Muzan's pupils shrank almost imperceptibly.
Impossible.
His blood had always been absolute.
"My lord…" Kokushibo said quietly, tilting his head as if curious, "would you like me to take more?"
Internally, his thoughts were far less restrained.
So this is all your power amounts to now?
But he concealed it perfectly.
Muzan's mind raced. The connection had been severed completely something had interfered. Something beyond his understanding.
And then
He remembered.
That gaze.
"Yes…" Muzan murmured under his breath. "That presence… it must be responsible."
Kokushibo feigned confusion. "My lord? Has something affected you?"
Muzan straightened immediately, regaining his imposing demeanor. Whatever had occurred, he would not allow it to show.
For now, he would observe.
He would wait.
"Kokushibo," Muzan said, voice low and commanding, "do not leave the Infinity Castle unless necessary."
A precaution.
Or perhaps fear.
Kokushibo lowered his head. "As you wish. Then allow me to remain here and devote myself to training."
That response nearly made Muzan falter.
Remain? Here?
Every moment Kokushibo stayed within the Infinity Castle now felt like standing beside a drawn blade.
But Muzan could not reveal that.
"…If you prefer another location," he said after a pause.
Kokushibo smiled faintly.
"If that would ease your concerns, my lord, I shall take my leave."
Before departing, he stepped closer too close and leaned near Muzan's ear, his voice barely above a whisper.
"If you require anything… do not hesitate to call upon me."
Then he vanished.
Leaving behind a still, silent chamber and a Demon King seated in quiet unease.
From afar, Nakime observed everything, her biwa resting across her lap. Her expression did not change, though her thoughts flickered briefly.
Even now… nothing is as it was before.
Far from the Infinity Castle, within the Demon Slayer Corps Headquarters, the atmosphere was entirely different.
Sanemi Shinazugawa trained relentlessly, his blade cutting through the air with violent precision. Each swing carried fury, resolve, and an unyielding desire to grow stronger.
He would not allow himself to remain weak.
Not in a world where demons like Kokushibo existed.
"Shinazugawa-san."
A calm, youthful voice interrupted his focus.
Sanemi paused, turning to see Muichiro Tokito approaching, his expression as serene as ever.
"What is it?" Sanemi asked, his tone unusually subdued.
Despite himself, he found it difficult to treat the boy harshly. Something about Muichiro reminded him too much of what he had lost.
Muichiro stepped forward and presented a small box. "I brought you something."
Sanemi raised an eyebrow, opening it to reveal neatly arranged sweets Hagi mochi.
"…Why?"
"You've been guiding my training," Muichiro replied simply. "It felt appropriate."
They sat together, an uncommon moment of quiet between two pillars of vastly different temperaments.
Sanemi ate without restraint.
Muichiro watched calmly.
Since joining the Corps, Muichiro had begun to understand the world more clearly. The distinction between humans and demons was not as simple as he once believed.
Yet one truth remained unshaken in his heart
No one would harm his great ancestor.
Not while he still breathed.
Elsewhere, within a quiet training hall, Giyu Tomioka practiced alone.
His blade flowed like water precise, efficient, without wasted motion. Each form of Water Breathing was executed flawlessly, yet his expression remained troubled.
It wasn't enough.
Against ordinary demons, this level of mastery was sufficient.
But against that presence…
Kokushibo.
The memory alone sent a chill down his spine.
He needed to grow stronger.
Far stronger.
Nearby, Shinobu Kocho continued her own training, her movements sharp but lacking the force required for decapitation.
No matter how perfect her technique, her physical strength imposed a limit she could not overcome.
And that frustrated her.
Deeply.
Her thoughts drifted to Mitsuri Kanroji, whose seemingly delicate frame concealed monstrous physical strength. Unlike Shinobu, Mitsuri could behead demons with ease.
It wasn't skill alone.
It was something innate something extraordinary.
Shinobu clenched her blade tighter.
If strength alone was insufficient…
Then she would find another path.
No matter the cost.
Meanwhile, far beyond their awareness, the balance of power continued to shift.
Unseen threads tightened.
And the world, slowly but inevitably, began moving toward a future none of them could yet comprehend.