[Kuromatsu-jō Ruins]
The wind hissed through the ruins of the castle.
As Kokushibo descended. He didn't jump; he simply appeared on the ground level.
"A human..." Kokushibo's voice was deep, resonating in his chest. "One who dispatched Upper Rank Five alone. You possess the Mark... Interesting. Draw your blade, child. Let us see if you are worthy of being remembered."
Kokushibo's hand blurred.
"Moon Breathing... First Form: Dark Moon, Evening Palace."
He performed a singular horizontal slash. Following the path of the physical blade, numerous chaotic crescent moon blades materialized, changing length and size unpredictably.
Manjiro's eyes widened as he realizes the spatial distortion. "That's not fair!"
Manjiro twisted his wrists, his blade humming. "Thunder Breathing... Second Form: Rice Spirit."
He unleashed five slashes in a single second to parry. He blocked the physical sword, metal screeching against flesh-steel, but the chaotic crescents trailing the blade slipped through his guard. They sliced his cheek and ribs, spraying blood onto the stone.
Manjiro winced, sliding back. "You're swinging the sword, but the crescents are a Blood Demon Art following the wake of the blade. It's a double-layered attack."
"A keen observation," Kokushibo stated, his face expressionless. "But knowing how you die does not stop the death. Moon Breathing... Third Form: Loathsome Moon, Chains."
He swung his sword rapidly in two crescent patterns. A storm of smaller crescent moon blades spread out, expanding until they filled the courtyard.
The noise was deafening. The castle walls disintegrated under the pressure.
"Thunder Breathing... Fourth Form: Distant Thunder."
Manjiro released ranged lightning strikes to detonate the moon blades mid-air, creating a barrier of explosions. He was forced back, his uniform shredded. He couldn't get close. As the Castle begins to crumble.
"You are fast," the demon noted, walking through the dust. "You rely on speed. But you move in straight lines. Thunder Breathing is predictable. I do not need to chase you. I simply need to place my blade where you will be."
---
[The Valley Below]
Down in the valley, Shinobu Kocho finishes guiding the last villagers to safety. She looks up at the mountain. It was no longer a peak; it is a crater emitting flashes of purple and gold light.
"An hour has passed..." Her hands trembled slightly. "What is happening up there? No human body can withstand that level of destruction for this long..."
A massive explosion rocked the ground beneath her feet, nearly knocking her over.
Shinobu gripped her haori. "Don't die, you idiot. You promised a double-suicide, didn't you? Don't you dare go alone!"
[Kuromatsu-jō Ruins]
Back at the Castle, Manjiro was exhausted. Every breath burned, his heart rate spiking to dangerous levels. Then, his vision blurred before sharpening into terrifying clarity.
A sensation like boiling oil flooded Manjiro's veins. On his neck, the dragon tattoo seemed to writhe, extending up his forehead and cheek. A crimson pattern emerged, locking into place.
The Demon Slayer Mark activated on its own. He could have used it from the beginning, but he avoided the strain. Now, he had no choice.
[SKILL: DEMON SLAYER MARK (PERMANENT)]
- Effect: A permanent mark of the "Golden Era." Grants immense physical enhancement. Unlike others, you are Immune to the age-25 curse.
[ACTIVE SKILL: TRANSPARENT WORLD]
Description: Extrasensory perception that turns the world into an X-ray overlay. The user perceives blood flow, muscle contraction, and lung expansion.Effect: Allows the user to predict attacks before the opponent moves.
Kokushibo's eyes narrowed. "Moon Breathing... Fifth Form: Moon Spirit Calamitous Eddy."
A defensive and offensive vortex of slashes rising from the ground, creating a column of blades.
Manjiro: (surprise) "The technique was performed without Kokushibo swinging his katana." (Manjiro is a fraction of a second late to react. He cannot block.)
He steps through the vortex of crescent moon blades. To Kokushibo, it looked like Manjiro phased through the blades. In reality, Manjiro saw the gaps between the air pressure waves and slipped through them.
"He... dodged the eddy?" Kokushibo's composure cracked. "How?"
---
Manjiro stopped ten feet away. He wiped blood from his mouth.
"You still wear the traditional kimono of a high-ranking demon slayer from the Sengoku era," Manjiro said, his voice flat. "Meaning you were once one of us. How boringly nostalgic. But looking at you... honestly, it's discouraging. You became a demon just to stay alive, didn't you?"
The air grew heavy. Kokushibo's hand gripped the hilt of his flesh-sword tight enough to bleed. "I sought... perfection. I sought the peak of the warrior's path. Death is for the weak who cannot leave a legacy."
"Your sword is made of your own cells, complete with its own eyes," Manjiro interrupted. "This tells me you no longer trust external tools. You are a man who needs total control over his environment, likely because you once faced someone or something you couldn't control at all."
Manjiro tilted his head. "You don't taunt, nor gloat. That's not 'warrior spirit.' It seems to me you have nothing left to say because your entire life was lived in the shadow of someone else."
---
Aggravated, Kokushibo's kimono tore away from the force of his expanding aura. His sword pulsed, growing flesh protrusions and extending into a grotesque Long Sword.
"Moon Breathing... Fourteenth Form: Catastrophe, Tenman Crescent Moon."
Using his altered katana, he performs a multitude of curved circular slashes which expand outward in every direction that incrementally grow in size, essentially creating an omni-directional vortex of crescent moon blades that whirls around him.
This technique is visually near-identical to Fifth Form: Moon Spirit Calamitous Eddy, albeit with much greater range.
Using the Long Sword form, the range triples, flesh protrusions extend the blade. With that attack he destroys the entire mountain peak. The shockwaves flatten the town below (now empty).
Manjiro was caught in it. There was no dodging this. His ribs were pulverized. His left leg shattered. He was thrown into the rubble like a ragdoll.
[UNIQUE SKILL: ZENKAI - 'WHAT DOES NOT KILL ME']
Description: An evolutionary trait. When the user is brought to the brink of death, their body adapts, permanently multiplying their base stats (Strength, Speed, Durability) to match the threat.
Status:ACTIVATED.
Manjiro lay in the rubble. His body was broken, but his energy was rising exponentially.
Kokushibo lowered his sword, walking toward the broken boy. "Why do you persist? Your ribs and leg are broken, your lungs punctured. You are barely hanging on. Become a demon. With your skills... you would rival even me in time. You could have eternity."
Manjiro spat a mouthful of blood, grinning wildly. "Eternity? Sounds boring. I'd rather burn out in a blaze of glory than rot forever in the dark with you."
Manjiro stands up. His broken leg snaps back into place through sheer muscle control. His aura shifted from yellow to a blinding gold.
"I understand it now."
Manjiro swung his Nichirin blade. He didn't use a Thunder form. He twisted his body, mimicking Kokushibo's exact posture.
"Moon Breathing (Imperfect)... First Form: Dark Moon, Evening Palace."
Manjiro swung his Nichirin blade. He didn't have the enhanced demon art to materialize crescent blades, but the sheer velocity and torque created a singular, massive crescent of vacuum pressure.
The wind blade collided with Kokushibo's attack, canceling it out completely.
Kokushibo froze. "You... copied my technique?! In the heat of battle? Without a Blood Demon Art? IMPOSSIBLE!"
Manjiro smirked, blood running down his chin. "It's a little stiff. I prefer my lightning. But thanks for the lesson, old man."
---