Outside the Infinity Castle, in the Swordsmith Village.
As the crimson moon in the night sky grew brighter, a man sleeping in a room suddenly sat up, unable to move at all.
Trembling all over, he struggled to put on his clothes and slowly made his way to the veranda that led to the courtyard. Despite his body being near death, he persisted in sitting there instead of lying down, gazing at the moon while coughing.
"Master Kagaya!"
Happening to enter the room with medicine, Kagaya's wife, Amane, hurried forward to support him.
"You can't do this, Master, you can't get out of bed right now!"
Amane's voice was anxious and concerned.
"Don't worry about me, it will be over soon..."
Kagaya calmly patted his wife's hand and spoke in his usual gentle tone.
"I can feel it, Kibutsuji Muzan is in battle."
Like a last burst of light, Kagaya's voice returned to normal, no longer as strained or pained, but filled with indescribable calm and gentleness.
"I suppose His Excellency has already found him and is currently fighting him?"
Kagaya didn't know the outcome of this battle, but he knew this would be the last time he sat here like this.
If Riezel defeated Muzan, the curse on the Ubuyashiki family would be lifted, and he might overcome his illness and return to being a normal person.
If Riezel couldn't defeat Muzan and the demons achieved ultimate victory, with his current physical condition, he would likely die immediately.
Even if Muzan escaped and the curse remained, this would still be his last time sitting here.
Moreover, he had a feeling that if Muzan wasn't eradicated before dawn, this might also be the end for him.
If that were the case, in this final moment, he preferred to sit here like this, instead of lying in bed, watching the moon until it was replaced by the sun of the following day.
"It's really frustrating..." Kagaya murmured to himself. "At a time like this, I can't fight like those children, picking up a sword and fighting alongside them... I can only sit here quietly, waiting for the outcome... Ubuyashiki is a cursed family from any perspective..."
"...Please don't worry too much." Amane said gently, supporting her husband. "Thanks to Lord Tsugikuni, everyone has changed. If it's them now, they can surely prevail against the Upper Ranks."
"Umm... I believe in that too..."
Kagaya nodded with a gentle expression.
"They will definitely defeat the demons, overcome this thousand-year tragedy, and set everything right."
"Tsugikuni Yoriichi, his appearance is a sign... a proof..."
"Whether it's the one from the Sengoku era or this one from our Taisho era, it's the same..."
Kagaya turned to his wife.
"Thank you for all these years of hard work, Amane."
Upon hearing this, Amane almost couldn't hold back her tears for a moment, but fortunately, she managed to.
"Don't worry, Master..." Amane said slowly. "The curse will definitely be broken in our generation. Whether it's us or our children, we won't suffer like this again in the future."
"I believe that..." Kagaya said with a faint smile. "I've always believed..."
At this moment, the couple embraced each other, sitting under the full moon, quietly awaiting the final outcome.
Before long, their children also came in, surrounding their parents and embracing them silently, waiting for Riezel's victory.
===
Not only the Ubuyashiki family but everyone paying attention to this final battle was the same, each in their own way, awaiting the final outcome.
Including the members of the Demon Slayer Corps currently trapped in the Infinity Castle, they were all the same.
'We must win!'
Gyoumei and Shinobu, who were fighting Upper Two Douma, silently prayed in their hearts.
'We must win!'
Kyoujurou, locked in a fierce battle with Upper Three Akaza, exclaimed firmly in his heart.
'We must win!'
Sanemi and Giyuu, entangled with the clones of Upper Four Hantengu while searching for his main body, shouted in their hearts as they wielded their swords.
'We must win!'
Obanai and Tengen, trapped by Nakime's Demon Blood Art and constantly struggling through changing terrain, also prayed.
'We must win!'
Mitsuri, who had beheaded countless tigers and pushed Upper Six Torasei to the brink, along with Muichirou, prayed to the heavens.
""We must win!""
Shouting together, Zenitsu and Inosuke, though covered in wounds, refused to give up as they continued to charge toward Upper Seven Kaigaku.
*WHOOSH!*
Tanjirou transformed into flames, but these were no longer the destructive ones from before. They radiated high temperatures and a reddish hue like the sun, akin to sun flames that purified everything.
At this moment, Tanjirou finally unleashed 'Hinokami Kagura (Sun Breathing)', passed down through generations of the Kamado family from Yoriichi.
"WE MUST WIN—!"
Tanjirou's voice, carried by the sun's flames, echoed into the sky.
===
*BOOM!*
A thunderous roar erupted, causing the entire cliff-like structure to tremble.
At the pinnacle, a shockwave exploded, sweeping outwards like a storm, as if capable of rending heaven and earth.
Atop the place called the throne, Riezel and Muzan clashed relentlessly.
*BOOM!* *BOOM!* *BOOM!* *BOOM!*
One enveloped in flames, the other wielding bladed flesh whips with frenzied ferocity—they collided, unleashing a staggering impact.
In the process, the ground ruptured beneath their feet, sending shards of rock and debris soaring into the air.
"Lady Tamayo!"
Yushirou shielded Tamayo, shouting over the tumultuous winds and shockwaves.
"It's too dangerous here! We need to retreat!"
Yushirou grabbed Tamayo, preparing to pull her away, but unfortunately, she shook off his grasp, bravely resisting the storm.
"No! I must stay and watch!"
Tamayo yelled, her gaze never left the battlefield.
Yes, how could she leave now?
Kibutsuji Muzan, the abomination who had altered her own existence, a monstrous being who had wrought unforgettable sorrow upon herself and others, was now being brought to justice.
He had slaughtered too many lives.
He had created too many tragedies.
His very existence was the world's greatest sin.
Now, a man bearing the name 'Tsugikuni Yoriichi' prepared to defeat him, to annihilate him, to exact vengeance upon this demon.
How could she leave at such a pivotal moment?
She had dreamed of this moment every day.
She believed that every human fighting tonight, everyone aware of this event, and everyone keeping track of the unfolding battle was awaiting Muzan's demise.
As the closest witness, how could she walk away and miss it all?
"I must witness it!"
Tamayo clenched her fists tightly, nails digging into her palms until they drew blood, letting it flow freely.
"I must see that monster die here, before my eyes!"
For her, it was a right and an honor reserved for her alone.
Centuries ago, she had nearly witnessed Yoriichi's sword end Muzan's life.
Centuries later, here she stood, ready to witness it truly happen.
With this resolve, Tamayo refused to retreat even a single step and braved the storm, her body exposed to the onslaught. Even if struck in the forehead by flying debris, even if her thighs were slashed by rubble, and drenched in blood from head to toe, she would not retreat.
"Lady Tamayo..."
Yushirou watched as Tamayo gritted her teeth and endured everything, deeply moved. No longer advising or stopping her, he stood with her against the raging wind, silently persevering.
*BOOOM!*
Suddenly, another rumbling sound erupted, unleashing an even more violent shockwave that blew away the two who had persevered so bitterly.
Amid the shockwave, Riezel and Muzan's figures appeared in a flash.
"DIE!"
Shouting with anger, Muzan swung his thin, tendril-like whips wildly at Riezel.
Muzan's primary means of attack consisted of two methods.
One was transforming his physical body, turning his two arms into versatile, rock-solid defensive and offensive whips.
Not only was their attack range extremely wide, but the bladed protrusions on them could also change position and shape at will, swinging at incredible speeds.
Normally, even those who had used the Transparent World would find it difficult to react, as their destructive power and speed were astonishing, capable of easily destroying a house with a single strike.
In fact, the attack power and speed were such that even Yoriichi in his prime would shiver upon first encountering them, indicating the sheer power of these whips.
Moreover, since these whips carried Muzan's blood, they were capable of destroying their target's cells at his will and, in theory, would cause instant death to anyone struck by them.
Not to mention the numerous 'mouths' on the whips that generated immense suction during attacks, creating whirlpools in the air, immobilizing those nearby, and tearing everything apart, making them even more deadly.
Given this, Muzan's arms were clearly his deadliest weapons, and no human with flesh and blood would dare to be hit by them, not even to sustain a graze.
Despite this, his second method of attack was equally formidable.
It was what Muzan was doing at the moment—wildly swinging several thin, tendril-like, bladed whips that extended from his body toward his opponent.
Not only did each of these thin whips move at astonishing speeds, imperceptible even to the Transparent World, but, like his arm whips, they also carried his blood, so that a single hit would destroy cells and lead to death.
Muzan's body boasted a total of seventeen such thin whips—nine on the upper body and eight on the lower body.
Even more so, the speed of the thin whips from the lower body surpassed that of those from the upper body, generating sonic booms capable of easily fracturing the earth during attacks—clearly demonstrating their terrifying power.
Currently, Muzan controlled these seventeen thin whips, ruthlessly attacking Riezel with maximum force.
Caught in the sudden whirlpools and sonic booms caused by Muzan's whips, Riezel found his movements slowing and himself subjected to attacks from all directions.
*BOOOM!*
Another thunderous roar echoed once again.