At this moment, a three-way standoff had formed within the massive Infinity Castle.
On one side sat Muzan Kibutsuji, perched high upon his throne. Behind him stood his legion of demons, surrounded by an ambush of heavy artillery and machine guns. Bathed in sunlight, their arrogance surged to the heavens, exuding a terrifying aura that intertwined the sacred with the profane.
On another side stood the entire Demon Slayer Corps, led by Kyojuro Rengoku. Their strength had skyrocketed, and their fighting spirit had climbed to a level capable of boiling the seas and burning the skies. Their aura was pure and blazing—the unyielding fire of human vengeance that had endured for a millennium.
Caught in the middle was a group of visitors with wildly clashing aesthetics. Hailing from different worlds, these "Hashira" were still in varying states of bewilderment and vigilance.
"Sasuke!"
Naruto Uzumaki's trademark loud voice shattered the eerie silence like a sudden clap of thunder.
He seemed completely oblivious to the palpable tension in the air, excitedly waving his arm at Sasuke Uchiha in the distance with his signature bright smile.
"Hey, what are you doing here! What a coincidence!"
Hearing that familiar, headache-inducing voice, the corner of Sasuke's stoic mouth twitched violently.
"Shut up, you deadlast."
The First Hokage, Hashirama Senju, looked at this energetic junior with immense curiosity.
He could sense the powerful life force within the boy, and the ninja headband indicated he was a shinobi of the Hidden Leaf.
He turned his head, looking at the "Jinchuriki" behind him—each possessing a different aura, yet all containing chakra familiar to him.
"Hashira..."
"Jinchuriki..."
The man hailed by future generations as the "God of Shinobi" stroked his chin, falling into a deep brainstorm.
Suddenly, a spark of inspiration hit him. He clapped his hands together as if he had figured everything out.
"I've got it!"
Hearing Hashirama, Naruto and the others turned to look at him simultaneously. They were all curious about what this legendary First Hokage, a man of both wisdom and power, had deduced.
Instead, Hashirama declared with absolute seriousness, "I've got it! I must be dreaming!"
"..." Naruto stared in deadpan silence.
Suddenly, one figure could no longer hold back and took the initiative to break the stalemate.
The man with bulging muscles and wildly flowing hair—Kars, who proclaimed himself the "Ultimate Being"—burst into maniacal laughter.
His gaze bypassed everyone else and landed squarely on Muzan Kibutsuji upon the throne.
He could sense a trait within Muzan that was similar to his own, yet distinctly different.
He wanted to experience firsthand just how capable this world's "Ultimate Being" truly was.
In the next instant, Kars vanished from his spot.
He transformed into a streak of purple light, moving too fast for the naked eye to track, and charged at Muzan. Mid-dash, his arm morphed into a gleaming, razor-sharp blade, aiming straight for the head of the man on the throne.
His movements were elegant, yet they harbored a fanaticism capable of tearing through anything.
"Insolent!"
Muzan's pupils shrank sharply as a surge of fury erupted from him.
This sudden interloper actually dared to draw a blade against him—he was simply courting death.
He swung his hand fiercely.
"Kill them!"
"Slaughter every last one of these bugs, wherever they came from!"
Obeying the divine command, the demon legion moved instantly.
Unleashing heaven-shaking roars, they swarmed from all directions toward the "visitors" in the center of the battlefield.
The demons' actions immediately clarified who the enemy was for anyone still out of the loop.
"Wood Release!"
The First Hokage, Hashirama Senju, slapped his hands together, and a boundless life energy erupted from his body.
He prepared to use his Wood Release ninjutsu to temporarily bind all the charging demons.
Beside him, Sasuke Uchiha moved even faster.
His blood-red Mangekyo Sharingan and the mysteriously rippling Rinnegan had already locked onto Muzan Kibutsuji on the throne.
"Susanoo!"
Purple energy shot into the sky as a colossal, ominous skeletal figure began to slowly materialize behind him.
Just as a massive free-for-all threatening to engulf everyone was about to erupt...
A booming shout, as fierce as fire, overpowered the cacophony.
"Ignore those people!"
Kyojuro Rengoku raised his scorching blade—forged from solidified flames—high into the air, his entire body igniting with golden solar fire capable of incinerating all creation.
"We have only one target!"
"Slay Muzan Kibutsuji!"
Before his words even faded, he transformed into a blazing meteor, tearing through the roaring air as he charged straight for the throne.
"Bring it on!"
Muzan did not retreat; instead, he stepped forward, a cruel smile surfacing on his face.
"I will show you the true power of an Ultimate Being!"
He stood up abruptly from his throne, a sickening series of bone-cracking sounds echoing from his back.
Squelch! Squelch! Squelch!
Dozens of hideous bone whips, covered in a metallic pitch-black shell and tipped with razor-sharp bone spikes, frantically extended from his back, thrashing wildly in the air like living creatures.
That was the ability he had acquired from those newly created Demon Generals.
Now, these bone whips simultaneously intercepted the lethal attacks coming from two different directions.
Several whips lashed out at Kars, while dozens more formed an impenetrable shield wall, blocking Kyojuro Rengoku's charging path.
BOOM!
The absolute apex fighters violently clashed in the center of the Infinity Castle.
"Fire!"
At Muzan's command, the heavy artillery and machine guns hidden within the twisted architecture of the Infinity Castle unleashed a deafening roar.
The pitch-black muzzles spat out tongues of deadly fire. Countless artillery shells and bullets wove together into a dense net of firepower, blanketing the entire battlefield.
The Upper Rank demons also made their move.
Wearing bloodthirsty smiles, they sought out prey that caught their interest.
Upper Rank Two, Doma, immediately spotted the petite figure wearing a butterfly-wing haori in the crowd. He suddenly recalled that he seemed to have killed a girl who looked somewhat similar to her in the past.
The fake smile on his face instantly grew incredibly radiant. With a flash, he appeared in front of Shinobu Kocho, the golden fans in his hands radiating a bone-piercing chill.
"Oh my, beautiful miss, are you perhaps lost?"
Meanwhile, the six eyes of Upper Rank One, Kokushibo, were locked dead onto Sasuke Uchiha, who was manifesting his Susanoo.
His intuition as a fellow swordsman, combined with the sense of threat emanating from those eyes, prompted him to draw his demonic blade without hesitation and charge forward.
Elsewhere.
Upper Rank Three, Akaza, who pursued the absolute pinnacle of martial arts, immediately set his sights on Muichiro Tokito, who was effortlessly and gracefully slicing through demons in the chaotic battlefield.
"Technique Deployment!"
"Destructive Death: Compass Needle!"
Akaza roared in excitement as a snowflake-shaped formation expanded beneath his feet. He turned into a blur, charging straight at the peerless, genius swordsman.
An unprecedented, chaotic battle officially raised its curtain at this very moment.