Final Battle

... Boommmm...

The thunderous explosion shook the night, flames soaring high into the sky. The red-orange glow illuminated the faces of the Hashira, who, despite anticipating this, could not hold back their tears of sorrow.

"Oyakata-sama!!!" The cry echoed, filled with grief and loss. Sanemi, with deep respect for Kagaya, was the first to run toward the direction of the explosion.

Before him lay Kibutsuji Muzan, sprawled in a horrific form—a mass of flesh with spiky tentacles writhing all over his body. Without hesitation, Sanemi attacked.

"First Form: Dust Whirlwind Cutter!" he shouted, his sword slashing repeatedly and rapidly, creating a lethal horizontal cyclone pattern.

Behind him, the sound of another attack echoed, accompanied by the other Hashira preparing to launch their assaults.

"First Form: Unknowing Flame!"

"First Form: Serpentinit Bipolar!"

"Fifth Form: Sea of Clouds and Haze!"

The other Hashira followed suit, attacking without hesitation. Although they mourned Kagaya's death, they knew that now was not the time to grieve; what they had to do now was kill Muzan while he was in a weakened state, ensuring that Kagaya's death would not be in vain.

However, as they launched their attacks, a biwa's sound resonated in the night sky. Below them, a traditional Japanese-style door appeared, and without warning, they fell through it.

At the same time, Kibutsuji Muzan also entered the door.

"Remember, Tamayo, Yushiro, Kanao, you must quickly control and kill Nakime before Kibutsuji Muzan can unravel the medicine in his body!" Haru shouted before jumping through the door with Shinobu in her arms.

.....

Various buildings flipped in the Infinity Castle, creating a bizarre atmosphere. Doors swung wide open, releasing members of the Demon Slayer Corps who fell from the ceiling. Relying on their skills, they landed steadily.

At this moment, the positions of the Hashira were separated and scattered throughout the Infinity Castle.

Haru hugged Shinobu's waist tightly, fearing they would be separated. She was worried Shinobu would encounter an Upper Rank Kizuki.

Thanks to that firm grip, they landed in the same location within the Infinity Castle. However, as soon as they landed, hundreds of demons immediately surrounded them.

"Fourth Form: Striking Tide!" Haru didn't wait. A flurry of attacks was unleashed, her sword slicing accurately and swiftly, decapitating the attacking demons.

"Dance of the Dragonfly: Compound Eye Hexagon!" Shinobu followed with a lethal attack, six consecutive thrusts striking at the demons, injecting wisteria poison into their bodies.

The demons fell, but despite witnessing their comrades die, they showed no fear. They attacked with increasing ferocity, as if they had no sense of dread.

Haru and Shinobu worked together, fending off the waves of lower-level demons that kept coming. Each attack was met with a counterattack, and they moved gracefully, dodging strikes while delivering lethal counterattacks.

Meanwhile, in another part of the Infinity Castle, the Hashira and other Demon Slayer members were also engaged in their respective battles. The sounds of swords clashing and demons screaming filled the air, creating a horrific symphony.

Sanemi, separated from the others, faced the strongest Upper Rank Kizuki, Kokusibo.

Kokusibo sat calmly, seemingly indifferent to Sanemi. Even so, Sanemi felt extraordinary pressure. He knew how powerful this demon was based on the information Haru had given. With his strength, there was no chance of victory, but he was not afraid. Since joining the Demon Slayer Corps, he had prepared to die.

Gripping his Nichirin blade, Sanemi dashed toward Kokusibo.

"First Form: Dust Whirlwind Cutter!" Sanemi launched a series of more than ten horizontal slashes in an instant, like a storm ready to tear apart anyone in its path. His swift and accurate movements created an illusion of swirling wind surrounding Kokusibo.

Kokusibo opened his six eyes, glowing in the dim light of the Infinity Castle. Calmly, he stood and grasped the hilt of his katana. With a gentle movement, he drew his sword and faced Sanemi.

"Sixth Form: Perpetual Night, Lonely Moon - Incessant."

In an instant, Kokusibo unleashed a series of curved slashes that sliced through the air, creating wild crescent blades of moonlight. The attacks flew toward Sanemi, effortlessly deflecting all the slashes he had launched. Sanemi was shocked to see how Kokusibo could counter such rapid strikes.

Kokusibo possessed the Transparent World, allowing him to see more than just Sanemi's body. He could see the flow of blood, the movement of muscles, and even Sanemi's breathing patterns, making it possible for him to predict every move Sanemi would make.

Sanemi felt overwhelmed. He knew that every attack he executed was already anticipated by Kokusibo. However, he had no intention of retreating or showing fear on his face.

He took a deep breath, trying to calm his racing heart.

With a sudden movement, Sanemi launched his second attack.

"Second Form: Claw, Purifying Wind."

Sanemi raised his sword to the right and unleashed four vertical slashes simultaneously toward his enemy, resembling claws aimed at Kokusibo.

However, Kokusibo gracefully evaded the attack.

"You are too slow," he said, elegantly moving his katana.

"First Form: Dark Moon, Evening Palace."

Kokusibo drew his katana and performed a single horizontal slash following the crescent moon shape, creating countless chaotic crescent blades along its path before sheathing it again.

.....

"Fifth Form: Swaying Love, Wildclaw."

Mitsuri leaped into the air, performing a somersault and unleashing a flurry of fast, winding slashes from a distance, forming a storm of cuts that severed the arms, legs, and heads of Zhakuten, Hantengu's clone, who was dodging Zenitsu's attacks.

At the same time, Tanjirou relied on his sense of smell to locate the main body of Hantengu hiding in a trembling corner.

"First Form: Dance."

Without hesitation, Tanjirou struck with a vertical circular slash like a sun wheel, beheading Hantengu, who stared in fear.

"… Ga-ga-ga-ga-follow me, Kibutsuji Muzan is in the center of the Infinity Castle."

The Kasugai crow, acting as their communication tool, immediately guided everyone toward Kibutsuji Muzan's location.

.....

The crescent blades slid along their path, creating wounds on Sanemi's body.

Pain coursed through him as Kokushibo's slash struck. The Demon Slayer uniform he wore was torn apart, and blood flowed freely from his injuries. Sanemi fell, but his spirit did not extinguish. He struggled to rise, determined to continue the fight.

However, Kokushibo showed no mercy. He stepped forward with an unexpected speed, the next slash hitting Sanemi before he could react. The pain gnawed at him, but Sanemi ignored it all. He gathered all his strength, trying to fight back.

As Sanemi struggled, footsteps sounded behind him. Gyomei Himejima, the Stone Pillar, and Tokito Muichiro, the Mist Pillar, arrived to assist.

"First Form: Serpentinite Bipolar!"

Gyomei's axe and iron ball attacked Kokushibo from a distance, alternating strikes.

"Fifth Form: Sea of Clouds and Haze!"

Tokito zig-zagged while launching multiple slashes at Kokushibo.

"Seventh Form: Mirror of Misfortune, Moonlit!"

Facing their attacks, Kokushibo countered with graceful and swift movements.

"Seventh Form: Mirror of Misfortune, Moonlit!" Kokushibo unleashed a massive crescent-shaped slash, creating a wave of attack that surged toward them.

Kokushibo's strike hit hard, forcing Gyomei and Tokito to brace themselves. The force released was so powerful that the ground trembled, and dust swirled in the air. Gyomei struggled to withstand the attack with his body, and although he was muscular, the impact was excruciating.

Sanemi felt a sharp pain throughout his body, but his fighting spirit was unyielding. Amid the chaos of battle, as Kokushibo launched a counterattack, Gyomei and Tokito united to protect each other and the fallen Sanemi.

"Sanemi! Get up!" Gyomei shouted, his voice booming amidst the din of battle. The axe and iron ball in his hands spun at incredible speed, creating winds that ruffled their uniforms.

Tokito surged forward with breathtaking speed, attacking Kokushibo.

With an arrogant stride, Kokushibo swung his sword, creating a dangerous circle that cut through everything around him.

"Fifth Form: Sea of Clouds and Haze!" Tokito shouted again, trying to divert Kokushibo's attention. Each slash created blurred shadows, but Kokushibo was still able to anticipate their movements.

"First Form: Serpentinite Bipolar!" Gyomei continued his assault, using his physical strength to inflict significant damage. However, Kokushibo cleverly evaded the attacks, countering with equal force, creating waves of energy that sliced through the air.

Kokushibo halted Gyomei and Tokito's strikes, his expression cold.

In that moment, Sanemi struggled to rise. Blood still flowed from his wounds, but his strong will kept him standing.

The battle raged on as Gyomei activated his Demon Slayer mark amidst the intense confrontation. Thanks to this, they had balanced power against Kokushibo.

With sharp movements, Kokushibo swung his sword toward Tokito, launching a deadly attack.

Tokito tried to dodge but wasn't quick enough. A slash flew through the air, and in an instant, his hand was severed. He fell, screaming in pain, blood pouring from the wound.

"Tokito!" Sanemi yelled, watching his friend fall. The pain deepened, but he knew they could not lose. He gathered every remaining bit of strength.

"Gyomei, I'll distract him; you attack with all your might, don't worry about me," Tokito said firmly.

Gyomei said nothing, only gazing at Sanemi with tears streaming down his face. He vowed to kill Kokushibo with the chance Sanemi had given him.

Sanemi ran swiftly toward Kokushibo, swinging his blade. He reached Kokushibo and stabbed his leg with his Nichirin sword while restraining Kokushibo tightly with his body.

Feeling he could not break free from Sanemi's grip, blades suddenly emerged all over his body and pierced Sanemi. Nevertheless, Sanemi refused to let go, even as his heart was pierced.

"Gyomei!!!!" Sanemi screamed with all his might.

Gyomei wasted no time and swung his axe, decapitating Kokushibo. Worried Kokushibo might become like Akaza, breaking the limits in the end, Gyomei destroyed the head and injected the human-altering potion into him.

Kokushibo felt no fear of death; he only recalled fleeting memories of his life as a human. Somehow, he felt at peace.

Kokushibo's body soon vanished into ashes, making Gyomei, Sanemi, and Tokito exhale deeply.

"Gyomei, I'm leaving now. Make sure to kill that bastard, Kibutsuji Muzan," Sanemi said as he felt the end of his life approaching.

"Don't worry. I will ensure he disappears from this world," Gyomei replied earnestly. He helped Tokito bandage his wounds to stop the bleeding. Kokushibo's body suddenly disappeared as they continued their journey according to the guidance of the Kasugai crow.

.....

Relying on Tamayo's illusions and Yushiro's Blood Demon Art, Tamayo, Yushiro, and Kanao finally arrived at Nakime's location.

They dared not act recklessly, knowing that Nakime could control the movements of the Infinity Castle, so they had to approach carefully to avoid raising her suspicion.

Using Tamayo's Blood Demon Art to create illusions, they concealed their presence and crept closer to Nakime.

With slow steps, they reached behind Nakime, and Yushiro immediately used his demon art to control her.

"Now, Kanao," Tamayo said seriously as she saw Nakime had been subdued.

... Swosh... Splash...

Without answering, Kanao swung her sword and decapitated Nakime.

With Nakime's death, who controlled the Infinity Castle, the place immediately shook as if it were about to collapse at any moment.

"Roar!!!" Kibutsuji Muzan, who was still unraveling the poison in his body, felt Nakime's death and roared in anger, his whip-like appendages destroying the surrounding environment.

The entire Infinity Castle continued to shake as if it were about to break through something.

....

"sigh..."

Haru and Shinobu sighed in relief as all the demons surrounding them were slain.

"It seems Tamayo and the others succeeded," Haru said as he sensed the Infinity Castle trembling.

"Let's head to where Kibutsuji Muzan is before it's too late," Shinobu suggested seriously.

"You're right."

Haru agreed, and they dashed toward the center of the Infinity Castle.

With Nakime's death, they no longer needed to navigate around to reach the heart of the Infinity Castle.