*Rumble—!!!*
It was the shaking sound of the earth.
At this moment, the cliff-like structure collapsed entirely like a mountain avalanche, finally crashing heavily onto the ground. It stirred up a violent gust of wind, causing the ground to tremble and sending billows of dust and smoke into the air.
*BOOM!* *BOOM!* *BOOM!*
Debris and rubble kept falling, creating frequent booming sounds that resembled a scene of mountains collapsing and earth splitting.
Amidst the chaos of collapsing mountains and splitting earth, the infinite flames of the sun ended, gradually dispersing the rising flames.
Currently, the giant baby had already vanished into ashes, disappearing without a trace, and even the body of the demon at its center had been completely incinerated.
Only his head remained, falling from mid-air like a dislodged rock, rolling on the ground for several rounds before finally coming to a stop.
"..."
"...How is this possible?"
After being silent for a while, Muzan murmured as he sensed his nonexistent body.
He refused to accept this reality.
*Step* *Step*
Suddenly, a faint sound of footsteps rang out, causing Muzan's vision to darken as a figure appeared before him.
Muzan subconsciously looked up.
Riezel appeared before him, holding a sword emitting intense heat, looking down at him from a higher position.
"It's over..." Riezel said calmly. "In the end, you still couldn't take the Blue Spider Lily from my hands."
Upon hearing this, Muzan's face twisted.
He desperately drove his own power, trying to regenerate his body, but under the double restraint of Riezel's sword and skill, his regenerative ability was already suppressed.
Now, with his entire body burned to ashes by Riezel's sunfire, even if he became stronger by breaking the limit again, it was impossible for all parts of his body except his head to regenerate quickly at this moment.
As Riezel had mentioned, it was over.
Realizing this, fear finally emerged in Muzan's heart.
After hundreds of years, since the last time he was severely injured by Yoriichi, Muzan once again experienced the feeling of fear.
He was going to die.
He deeply understood this, just as he had realized it more than three hundred years ago during the Sengoku period.
Realizing this, Muzan hesitated no more.
*BOOM!*
Suddenly, his entire head exploded directly into countless fragments, shooting in all directions.
Yes.
Muzan self-destructed.
Just like the time he was severely injured by Yoriichi during the Sengoku period, Muzan once again chose to self-destruct and split into countless fragments, crazily fleeing.
As long as a piece of his fragment escaped from here, with his power, he would eventually be able to recover.
It was Muzan's strongest escape method, something even Yoriichi couldn't do anything about.
Unfortunately, Muzan was not facing Yoriichi now, but Riezel, who was prepared and possessed powers and means beyond this world's understanding.
*Buzz—*
In the air, a sudden buzzing sound appeared, causing a faintly glowing barrier to shimmer into existence.
Yes, it was a barrier.
At this moment, Riezel finally used the power of magic, using the magic from the Structure System to construct a small barrier that completely isolated this area from the outside world.
*Peng!* Peng!* Peng!*
Fragments of Muzan's body relentlessly struck against the barrier, creating a series of banging sounds.
Pitifully, they were all blocked and unable to escape without exception.
"Just give up, you can't escape."
Riezel calmly watched everything unfold, extending his hand and clenching his fist in a gesture of restraint.
In the next moment, the barrier surrounding the area immediately began to shrink, gradually forming a square cube that fell into Riezel's hand.
Inside the barrier cube, countless fragments continued to impact the shield fiercely, yet they were completely unable to break through.
"What?! What the fuck is this?!"
Muzan shouted in shock and anger from inside the barrier cube, his voice filled with panic.
"I told you, it's over."
Riezel calmly watched the chaos inside the barrier cube.
"No! It's not over yet!"
Muzan wouldn't simply surrender without a fight, so in the next moment, he yelled into the void in agitation.
"Nakime! Get me out of here! Quickly!"
Obviously, this was another escape route he had planned.
By transferring all members of the Demon Slayer Corps to the Infinity Castle, he not only intended to use the castle's terrain to trap and annihilate them but also to secure a way out for himself in case of emergencies.
With Nakime controlling it, he could instantly be transported away, leaving the Demon Slayer Corps trapped.
In this way, he could permanently eliminate the entire Demon Slayer Corps and leisurely escape.
It had to be said that Muzan's plan was not bad, but he was about to be disappointed.
"Serpent Hashira Iguro Obanai and Sound Hashira Uzui Tengen have defeated the Upper Five! Serpent Hashira Iguro Obanai and Sound Hashira Uzui Tengen have defeated the Upper Five!"
"Upper Five! Defeated!"
"Casualties are zero!"
As several Kasugai Crows flew through the air and brought this news, Muzan was once again dumbfounded.
It was only then that he realized Nakime had disappeared.
Nakime, who controlled the Infinity Castle, was able to change its terrain at will and theoretically prevent enemies from ever approaching her, allowing for instant teleportation out of danger.
Yet, Nakime, who seemed impossible to defeat with this amazing ability, had actually been defeated.
"You think I haven't considered how passive I might become once inside the Infinity Castle?"
Riezel looked at Muzan's fragments that had settled within the barrier cube, speaking calmly and composedly.
"I knew you would choose to engage in battle within the Infinity Castle. I also knew that if we didn't deal with Upper Five Nakime, we would be trapped by this castle. That's why I warned the Demon Slayer Corps that once they encountered her, they must prioritize eliminating her."
As a result, when they encountered Nakime, even Obanai, who was eager to assist Mitsuri, had to set aside his intentions and engage Nakime directly.
Although Nakime's Demon Blood Art was troublesome, it still had a flaw—namely, every time she used it, she had to pluck her biwa.
Riezel informed all the Hashira of this fact, and based on this, each Hashira devised their own different strategies.
Among them, Tengen's strategy was particularly the most effective.
As the Sound Hashira, Tengen possessed sensitive hearing. While not as sensitive as Zenitsu's hearing, who could hear footsteps, heartbeats, and even someone's emotions from a great distance, he could still detect subtle sounds.
He also had a unique understanding of music, possessing an original combat calculation formula. By analyzing and converting the rhythm of an opponent's attack into musical notes, he could understand their attack patterns and blind spots.
Once he completed his calculations and successfully converted the rhythm into music, he could target the gaps in the rhythm to strike his opponent, much like adding harmonies to a song.
Such abilities were perfectly suited for dealing with Nakime.
As long as Nakime plucked her biwa in front of Tengen, he could quickly discern the pattern of her Blood Demon Art activations and take targeted actions, navigating around the changing terrain without being hindered by it.
Furthermore, with Obanai's ability to swing slashes that could turn corners from blind spots, seizing the opportunity to behead Nakime before she could escape while plucking her biwa wouldn't be too difficult for this Serpent Hashira, who had already awakened the Demon Slayer Mark and the Transparent World.
Unfortunately for Nakime, she encountered Tengen, who could counter her effectively, making her survival seem nearly impossible.
Of course, even if Nakime did survive, Riezel wouldn't allow her to transport Muzan out of Infinity Castle.
After all, not only did Riezel not neglect his studies of magic from the Interference System, but it was the magic system with which he had the highest compatibility. Therefore, even without mastering any particularly advanced magic from the Interference System, he could interfere with Nakime's Demon Blood Art.
In other words, from the beginning, Muzan had no chance of escaping using Nakime's Demon Blood Art.
Moreover, with Nakime defeated, the downfall of the other Upper Ranks was just a matter of time, as confirmed by the next news from the Kasugai Crows.
"Love Hashira Kanroji Mitsuri and Mist Hashira Tokitou Muichirou have defeated the Upper Six!"
"Upper Six! Defeated!"
"Casualties are zero!"
Facing an Upper Rank that controlled tigers, Mitsuri and Muichirou, both strength at Level 4 with their Demon Slayer Marks activated, felt little pressure confronting this demon and quickly beheaded him.
"Wind Hashira Shinazugawa Sanemi and Water Hashira Tomioka Giyuu have defeated the Upper Four!"
"Upper Four! Defeated!"
"Casualties are zero!"
Sanemi and Giyuu, both Hashira who had awakened the three abilities, were at the pinnacle of Level 4. Undoubtedly, the clones of Hantengu were no match for them, and it was only a matter of time before they found and killed the main body.
"Stone Hashira Himejima Gyoumei and Insect Hashira Kochou Shinobu have defeated the Upper Two!"
"Upper Two! Defeated!"
"Casualties are zero!"
Upper Two, Douma, was undoubtedly powerful, likely nearing the pinnacle of Level 4. Even with Shinobu using the Demon Slayer Mark, which only equated to upper Level 4, she was likely not a match for Douma.
However, with Gyoumei by her side, who was comparable to middle Level 5, Douma's defeat was inevitable.
"Flame Hashira Rengoku Kyoujurou has defeated the Upper Three!"
"Upper Three! Defeated!"
"Casualties are zero!"
Even Kyoujurou overcame his fated enemy, defeating Akaza who had killed him in the original work, achieving victory.
With the aid from the Demon Slayer Mark, capable of boosting one's strength by half a level, Kyoujurou, like Sanemi and Giyuu, now possessed strength equivalent to the pinnacle of Level 4.
Akaza, despite also being at the pinnacle of Level 4, fluctuated in power and lacked special abilities like the Transparent World, so his defeat by Kyoujurou was not surprising.
"Kamado Tanjirou, Agatsuma Zenitsu, and Hashibira Inosuke have defeated the Upper Seven!"
"Upper Seven! Defeated!"
"Casualties are zero!"
In the end, the three main characters also achieved a great victory, with no casualties, defeating the Upper Seven, Kaigaku.
With this, all the Upper Ranks had been defeated.
"..."
Muzan fell silent.
Inside the barrier cube, all his fragments ceased moving around and reformed into a head.
Muzan stared at Riezel, his eyes filled with fear and hatred.
"Why...?"
In his question, there was resentment and bitterness.