The entire Infinity Castle fell silent, leaving only the grotesque sound of Akaza's flesh regenerating at his neck as it tried to form a new head.
The noise was sharp and unsettling, like molten iron dropped into ice water, piercing straight through the bones.
Akaza's body twitched where it stood. Muscles, blood vessels, and bone writhed together at his neck, twisting like countless small serpents trying to rebuild what had been severed.
Everyone watched as Raiden calmly sheathed his Nichirin blade beside Akaza's body, their thoughts completely blank.
Blood still clung to the golden blade, dripping steadily onto the ground with faint, rhythmic taps.
Raiden flicked his wrist once, cleanly shaking off the remaining blood before sliding the blade back into its sheath.
"My strength has improved a little, but it is still not enough."
He had already sensed the change in Akaza's power the moment he stepped into the Destructive Kill, Compass Needle technique, but it made no difference.
To Raiden, demons were divided into only two categories, Kibutsuji Muzan and everything else.
No matter how strong Akaza had become, as long as he had not reached Muzan's level, he posed no real threat.
"Raiden…"
Tanjiro, who had witnessed everything, spoke under his breath.
He and Giyu had only managed to hold Akaza back with the combined strength of multiple Hashira. Even then, victory had never felt certain. Akaza had continued adapting to their fighting spirit, and the outcome had remained unpredictable.
Yet now, the same opponent had been beheaded in a single strike.
If Tanjiro could not still sense Akaza's presence from the severed head, he might have believed it was a substitute.
The difference was overwhelming.
Giyu stood in silence, his gaze fixed on Raiden's calm figure.
So this is his true strength.
In his mind, this was what a Hashira should be. Someone who stood above all others in the Demon Slayer Corps.
For a brief moment, the image of Sabito surfaced, overlapping with Raiden.
Both gifted. Both exceptional.
But Raiden was not anyone's shadow. He stood on his own, like the sun itself.
Rengoku looked at Akaza's fallen body, his grip on his Nichirin blade loosening slightly.
He did not feel sorrow.
Only regret.
Despite their opposing ideals, Akaza had been a worthy opponent. Rengoku had trained relentlessly for months after their last encounter, determined to face him again.
Yet Akaza had grown stronger as well, and even then, Rengoku had struggled.
Now, the outcome felt almost absurd.
The same demon who had pushed them to their limits had been cut down so effortlessly.
Raiden's strength truly lived up to its reputation.
Raiden's gaze rested on Akaza, whose body still struggled to regenerate.
"It is time to wake up. Koiyuki is still waiting for you."
His voice was quiet, yet it carried a weight that struck directly at the soul.
The moment Akaza heard that name, his entire body trembled.
The writhing flesh at his neck faltered, as if something inside him had suddenly seized.
For Raiden, killing Akaza now would have been effortless. No one present could have stopped him.
But instead, he watched.
Akaza was a demon responsible for countless deaths. His past could not be erased.
Yet somewhere within him, a trace of humanity still remained.
And Raiden saw it.
Akaza's eyes narrowed, his movements slowing.
Confusion flickered across his face, followed by pain.
Koiyuki.
The name felt familiar, yet distant. No clear image formed in his mind.
His head throbbed as if something buried deep inside was forcing its way to the surface.
The harder he tried to remember, the more his thoughts tangled.
His gaze drifted aimlessly, lost like a ship without direction.
Then his eyes fell upon the remnants of his technique on the ground.
The snowflake pattern.
Pure. Symmetrical. Unmistakable.
His heart trembled.
Why was his technique shaped like this?
The question had surfaced before, but he had ignored it.
Now, staring at the snowflake pattern, a deep sense of familiarity surged within him.
It felt important.
As important as that name.
Koiyuki.
Something connected them.
And suddenly, the barrier in his mind shattered.
Memories flooded back.
His eyes lost focus as if he had fallen into darkness.
Fragments pieced themselves together, becoming whole.
The snowflake merged with an image in his mind.
A girl in white.
A delicate snowflake hair ornament resting in her hair.
A gentle smile.
Eyes filled with warmth and hope.
"Koiyuki…"
The name slipped from his lips, barely audible.
But it carried unbearable weight.
In that instant, he understood.
The reason behind his technique.
The origin of the snowflake.
She had been everything to him.
His hope. His happiness.
And he had failed her.
The memories surged endlessly.
Akaza's body went still.
His struggle ceased.
His eyes turned hollow, drained of life.
It felt as though he was being swallowed by darkness, unable to escape the crushing weight of regret.
At last, he remembered.
Koiyuki.
The girl he had loved.
The one he could not protect.