The battle raged on beneath the blood-red sky as Kokushibo, the Upper Rank One demon, stood towering against his two most formidable foes: Gyomei, the Stone Hashira, and Muichiro, the Mist Hashira. The air was thick with tension as the three combatants faced each other, the weight of centuries of rivalry hanging in the atmosphere.
Gyomei gripped his dual weapon, the spiked flail and axe connected by a chain. His senses, heightened by his supernatural hearing, allowed him to hear every movement Kokushibo made, despite the demon's ghostly speed. Muichiro, his misty form barely visible through the shifting clouds of his Breathing Style, narrowed his eyes as he prepared for the fight of his life.
"Muichiro," Raja's voice echoed in his mind. "Kokushibo is your ancestor. The demon who turned To Muzan to suprass his brother Sun Hashira."
Muichiro's grip tightened on his katana as the realization hit him. His bloodline had been tainted by the very demon they now faced. The urge for vengeance pulsed within him, his Demon Slayer Mark lighting up, and his Diamond blue color Sword glowing with the fury of his resolve.
Without warning, Kokushibo unleashed his First Form: Dark Moon, Evening Palace, a singular, horizontal crescent-shaped slash that created chaotic blades of moonlight in every direction. Gyomei reacted instantly, swinging his Kusarigamajutsu with precision. The chain of his weapon wrapped around Kokushibo's crescent blades, deflecting them in all directions. But the demon was relentless, a dark smile curling on his lips as he prepared his next move.
Muichiro darted forward, using Mist Breathing: First Form: Low Clouds, Distant Haze, thrusting his sword forward with pinpoint precision. His strike was blocked by Kokushibo's Flesh Katana, which flickered with moonlight as it regenerated instantly. The force of the clash sent Muichiro skidding back, his breath labored as he recalculated.
"Impressive," Kokushibo said, his voice like a low rumble of thunder. "But it will take more than that to defeat me."
Gyomei, his immense strength apparent as he swung his Second Form: Upper Smash, attacked with both his flail and axe, forcing Kokushibo to leap back to avoid the crushing blows. But even as he retreated, Kokushibo unleashed his Second Form: Pearl Flower Moongazing, releasing three crescent slashes, each followed by a volley of crescent moon blades.
Muichiro, moving with blinding speed, used Mist Breathing: Third Form: Scattering Mist Splash to deflect the incoming blades, his sword whirling in a circular arc to protect himself. At the same time, Gyomei hurled his flail with a mighty Fourth Form: Volcanic Rock, Rapid Conquest, creating an explosion of force that caused the ground beneath them to crack and splinter.
But Kokushibo wasn't done. With a malicious laugh, he slashed with his Third Form: Loathsome Moon, Chains, sending two wide, crescent-shaped slashes that carved through the earth. The sky seemed to darken further as the very air became thick with the falling crescent blades.
Gyomei grunted and activated his Slayer Mark, using his Stone Skin to deflect one of the blades with his massive axe, but the second slice tore through his shoulder. The pain was immense, but his endurance was greater. With a roar, he slammed his axe into the ground, sending a shockwave through the earth that temporarily staggered Kokushibo.
Muichiro, sensing an opening, immediately used Mist Breathing: Sixth Form: Lunar Dispersing Mist, performing a series of somersaulting slashes that broke through the demon's defenses. Each strike sent a burst of mist into the air, disorienting Kokushibo for a brief moment. His movements were erratic, but his speed remained unmatched.
"Impressive," Kokushibo muttered. "But you are merely children playing in the shadows of the moon."
With a fierce roar, Kokushibo unleashed his Moon Spirit Calamitous Eddy. A violent vortex of crescent moon blades spun from his katana, cutting through the air in every direction, forcing Gyomei and Muichiro to dodge and weave with every ounce of their strength. The storm of blades threatened to overwhelm them, but both Hashira fought with unrelenting ferocity.
The battle dragged on, each of the warriors pushing their bodies beyond their limits. Muichiro, still reeling from injuries, activated his Demon Slayer Mark once more, his speed and strength surging. He slashed through the air with Mist Breathing: Seventh Form: Obscuring Clouds, disorienting Kokushibo, who struggled to predict the erratic motions of Muichiro's sword.
Gyomei, too, unleashed his Arcs of Justice, a barrage of strikes that seemed to come from every direction at once. Each blow collided with Kokushibo's flesh, tearing into the demon's skin, but Kokushibo's regeneration kept him whole. Still, the fight was taking its toll.
Gyomei's heart raced in his chest. He knew that Kokushibo's strength was waning, but so was theirs. The damage was piling up, and the moment of opportunity was fleeting.
Kokushibo's grotesque form was beginning to show signs of strain. His grotesque, demon form shimmered, the speed of his attacks slowing as his regeneration struggled to keep pace with the brutal onslaught from the two Hashira. He staggered slightly, and in that moment, Muichiro saw it.
The Transparent World flared in his vision. He saw Kokushibo's internal structure, the way his blood flowed, the core of his being. A single, decisive strike would end this.
"Muichiro!" Gyomei shouted, his voice booming through the chaos. "Now!"
With a final, desperate surge of energy, Muichiro launched himself forward, his sword glowing with intensity as he used Mist Breathing: Second Form: Eight-Layered Mist. Each slash came faster than the last, cutting through Kokushibo's defense with precision and power.
But it was the last strike that ended it all.
Muichiro twisted in mid-air, his blade descending with the force of a storm. He called upon everything—the rage, the grief, the endless drive for vengeance that had burned in him ever since Raja's words. His katana cleaved through Kokushibo's heart, severing the demon's life force in one clean strike.
Kokushibo's eyes widened in shock as his body began to disintegrate into dust, the last of his strength fading away.
For a moment, there was silence. The battle had ended.
Muichiro fell to his knees, exhausted beyond measure, his sword still glowing. Gyomei, breathing heavily, stood beside him, his body battered but unbroken.
"He was your ancestor," Gyomei said, his voice soft. "But you have surpassed him, Muichiro."
Muichiro didn't respond. He could barely comprehend what had just happened. The anger, the grief—it all felt so distant now. But one thing was certain: Kokushibo was dead, and the curse of his bloodline was finally broken.
As the dust settled, the two Hashira stood together, victorious, but at a tremendous cost.