In the days that followed, tragedies continued to unfold across the outside world. From time to time, the crow would bring reports of demons wreaking havoc in various places, slaughtering civilians, and attacking the Wisteria Crest Houses.
Yet the entire Demon Slayer Corps displayed astonishing restraint.
Every member had entered a state of tense anticipation. All the anger, grief, and unwillingness were transformed by the young swordsmen into a nearly self-destructive drive for training.
In the courtyard, the sound of wooden swords striking echoed from early morning until deep into the night.
Even the gentlest members now swung their blades with a ruthless determination, as though ready to perish alongside their enemies.
Asuka stood beside the waterfall in the back mountain, watching the raging torrent at his feet.
Beside him stood two solemn elders and comrades.
Sakonji Urokodaki wore his tengu mask, his voice hoarse yet powerful.
"Your breathing and sword forms are already close to perfection, Storm Hashira. As long as you grasp the circulating flow of Water Breathing, you will be able to further tame the violent power within your body."
Nearby, Giyu Tomioka remained taciturn as always. Under Urokodaki's instruction, he swung his Nichirin Blade, drawing arcs of deep blue light through the air.
"There is no constant formation in war, and water has no constant shape," Urokodaki said.
"Water can flow quietly, yet it can also split mountains and crack stone. Because it has no shape, it can become any shape."
"Become water, Asuka. Learn the flow between softness and strength."
Asuka closed his eyes and gripped Nugata at his waist.
The long blade seemed to sense its master's state of mind and emitted a faint humming sound.
He began adjusting his breathing according to Urokodaki's teachings.
Now, Breathing Techniques were no longer merely martial arts that strengthened the body. To him, they had become a conceptual method for understanding how to use his power.
By integrating spiritual particles into his breathing, his strength was no longer confined to fixed techniques.
"The power of fire seeks fierceness; the movement of water seeks continuity..." Asuka murmured.
Strange phenomena began to appear around him. A spiral current of energy mixed with deep blue and dark crimson surged violently, causing Urokodaki, who had only mastered mortal martial arts, to grow solemn.
"The surge of thunder seeks speed and decisiveness; the wildness of wind seeks freedom..."
"And the steady rock that embraces all..."
With the remnants of ancient texts left behind by Ubuyashiki, along with the wholehearted guidance of the Stone Hashira and the Water Hashira, he was attempting to merge the forces of every breathing style into a completely new Breathing Technique.
Was this Sun Breathing? He did not know.
But he could feel that his physical strength had already surpassed the limits of ordinary humans.
Asuka suddenly opened his eyes and slashed horizontally with the blade in his hand.
A strange black-red sword aura carrying intense heat burst forth from the tip of his blade.
Those sword energies intertwined in the air, vaguely forming a blazing sun wheel with razor-sharp edges.
In that instant, the waterfall's torrent was forcibly severed by an invisible force.
Even the falling water could not disperse the burning sword aura for a long time, instead splitting to fall along both sides.
And with that strike, he had not even released the power of Nugata. It was purely his sword aura that had stirred the spiritual particles in the air.
Behind his mask, Sakonji Urokodaki's pupils shrank violently.
From that power he sensed destruction—something purer than the demons themselves, something he had never witnessed before.
Giyu Tomioka also tightened his grip on his Nichirin Blade, a trace of astonishment flashing in his eyes.
Asuka sheathed his sword and gently pressed his chest.
A dull pain lingered in his lungs and organs. This forcibly fused breathing method placed tremendous strain on his internal organs.
"So it really is different," Asuka muttered while looking at his own hand.
Over the past few days, he had repeatedly observed Tanjiro demonstrating the Hinokami Kagura.
That sacred dance resembled the movements of a deity, each step and strike carrying a benevolent yet majestic aura that illuminated all things.
But the technique he had just used...
"It seems my Sun Breathing does not possess the warmth of sunlight," Asuka said calmly.
But it should still be enough.
Those who reach the same ultimate path will arrive at the same destination.
As long as he could cut off Kibutsuji Muzan's head, even if this power had deviated somewhat from the original path, Asuka did not care.
Three more days passed.
That day, while heading toward the training ground, Asuka encountered Tanjiro hurrying along with a large box strapped to his back.
"Mr. Asuka!" Tanjiro stopped. The mark on his forehead seemed deeper than it had been a few days ago. "Has your training progressed?"
"I've found a certain direction," Asuka said, looking into the boy's clear eyes. "What about you? Can your body handle it?"
"No problem! Mr. Rengoku has given me a lot of guidance. The movements of the Hinokami Kagura are becoming smoother and smoother!" Though exhausted, Tanjiro's eyes shone brightly.
"It's just... Zenitsu..."
"What about him?" Asuka frowned.
Ever since news arrived from Mount Sagiri that Jigoro Kuwajima had committed seppuku, that cowardly boy had completely changed.
"He's been in the back mountain for three days and three nights," Tanjiro said worriedly. "He doesn't talk to us, and he won't let anyone approach."
"I can feel it... the thunder there... it sounds very sad."
Asuka fell silent for a moment and looked toward the back mountain.
Sure enough, golden lightning occasionally flashed beneath the dark clouds.
Had the boy who once cried and screamed about wanting to find girls finally grown into a true swordsman through blood and tears?
"Let him be," Asuka said as he walked past Tanjiro and continued forward. "Some mountains must be climbed alone. Some revenge must be taken alone."
Late at night, the Ubuyashiki estate.
The moonlight tonight was especially desolate. Thick clouds hung in the sky like a massive burial shroud, completely blocking the starlight.
Because Shinobu Kocho's injuries had not yet healed, the entire estate's medical coordination had fallen to Kanao Tsuyuri and several young members.
To prevent the Hashira fighting on the front lines from losing focus, news about the worsening condition of the Master and Shinobu Kocho's severe injuries was being strictly concealed.
Within the inner residence, Ubuyashiki Amane and two children quietly kept watch beside Kagaya.
Kagaya no longer had the strength to speak.
A faint scent of decay lingered around his body. Bandages covered him from head to toe, yet he continued to face the direction of the courtyard.
"They've... arrived..."
Kagaya suddenly whispered two extremely faint words.
Amane, standing beside him, trembled violently.
She had heard no sound and sensed no presence.
Yet in the next second, the entire sea of wisteria flowers around the Ubuyashiki estate withered instantly.
An unprecedented malice—so oppressive it made one want to vomit—suddenly enveloped the entire estate.
From the shadows of the courtyard, a man wearing a white suit slowly stepped forward.
His movements were as elegant as a gentleman attending a banquet.
But within those crimson vertical pupils lay madness and brutality accumulated over a thousand years.
The progenitor of demons, Kibutsuji Muzan.
"Finally... I meet you... Muzan... I knew... with this life of mine... you would personally come to kill me..."
"Ubuyashiki..." Muzan spoke softly, his tone dripping with arrogance. "To be honest, I find this deeply disappointing."
His gaze swept across the tightly closed doors and the seemingly undefended courtyard.
Within his perception, there was indeed no trace of those troublesome Hashira.
It seemed the intelligence was correct. Those self-proclaimed warriors of justice had all been restrained across various locations by the disposable pawns he had sent out.
"How ugly... such an ugly sight..."
Kibutsuji Muzan stood before Ubuyashiki Kagaya.
He looked down at Kagaya's deathly ill body just as he once looked down at his own sickly past self.
A surge of pleasure rose from the depths of his heart.