[Ubuyashiki Mansion]
All the Hashiras were gathered in a room, Kagaya absent. His illness had worsened, rending him unable to move too much.
"Oyakata-sama will not be able to attend this meeting."
Lady Amane declared as she gently sat at the head of the table.
Sanemi sighed, suddenly feeling wistful. Everything was suddenly just tiring.
"Well, I guess we can report to you then."
Gyomei nodded.
"The movements of the demon's are getting wild. We don't think we can keep their existence hidden from the world again." Sanemi explained, scratching his head.
"Yes. I noticed that too. However, we're at an advantage. We've slain all the Lower Moons and one Upper Moon is dead. The other..." Giyu paused, his eyes unfocused. "... is with Shinobu."
At the mention of her name, the mood in the room soured. No one was satisfied with Kocho's dismissal. However, they couldn't fully side with her too.
"We have another issue at hand." Gyomei said. "The demon slayer marks. Only Shinobu had unlocked hers. However, we can't contact her because of obvious reasons."
In fact, none of them had seen her since then. Only hearing of a short figure being spotted here and there in different villages.
"Well, we need Tanjiro to fully understand how to awaken the marks then." Obanai said curtly.
Lady Amane nodded.
"Alright. I'll arrange a training session with you all and him. I hope this works out. So finally, we can wipe out all demons."
....
In a distant forest, Shinobu sneaked through trees with smooth movements, ensuring that no one saw her. During the day, she had her moments of peace. However, at night, demons were always approaching her. And the cause?
Douma.
His scent was like a magnet to all demons. He remained blissfully asleep, though—leaving Shinobu with the workload of protecting his vulnerable self.
Dark bags were visible under her eyes as she lightly patrolled the place she'd hidden Douma.
Soon enough, she heard it. The faint, distant growl of a demon.
Her sword clicked in its sheath, the poison being changed.
'Almost.'
The demon's ragged breathing grew closer and closer until she could finally see it. The demon was huge, looking like a minotaur. Its red beady eyes instantly locked on Shinobu while its tongue flapped in wild anticipation.
The ground beneath it cracked as it lunged forward, claws raised to slash the little human.
"Insect Breathing. Dance of the Butterfly—Flutter."
Shinobu blurred. She appeared behind the demon even before he reached her and slashed the back of its neck.
Stumbling forward, the demon watched in horror as its body disintegrated, unable to understand how it had died.
Landing softly, Shinobu exhaled, her eyes darting around. The forest was quiet. Almost too quiet it creeped her out.
"Damn! I'm living in hell."
Smiling bitterly, she climbed up a tree. Her eyes wide and alert.
HOWL!!!
Suddenly, a mad howl shattered the tranquil night. Shinobu froze, feeling a cold sensation on her body.
'What was that...?'
She had never heard a demon sound like that. It was utterly terrifying.
Finally, she saw the demon. It looked like a normal human with sharp fangs and a purple line across its cheek. Wearing a worn out samurai armor, it hefted a black odachi on its shoulders. Although she knew it was strong, the number in its eyes alarmed her.
Lower Moon One.
As soon as she spotted it, it also saw her. Its eyes gleamed with ferocity as its mouth widened into a smile.
"You're that Hashira. The banished one."
His voice, raspy and thick, reached her clearly.
Her eyes sharpened. Then she smiled.
"Good you know. You can now die."
The distance between them blurred.
Oniyasha's grin widened into a snarl, and in an instant, he vanished. The ground exploded beneath his feet as his massive frame blurred forward with terrifying speed, his odachi carving through the air in a crimson arc.
Shinobu leapt sideways, her form nothing but a flicker of motion. The blade slammed into the ground where she had stood, tearing a massive crater into the forest floor. Dirt and roots exploded upward, trees toppling like matchsticks.
Before he could recover, Shinobu darted along his arm like a butterfly dancing on the wind, her Nichirin blade flashing as she struck at the gap between his armor plates.
Clink!
Sparks flew, but the blade didn't sink deep enough. Oniyasha roared, his muscles bulging, and swung his free arm at her like a hammer.
She barely flipped over it, landing lightly on a branch above. Her breathing was calm, her voice cutting through his rage.
"Not bad. But you're slower than the former Lower Moons."
Oniyasha looked up, fangs bared. "You mock me, insect?!"
The air trembled as Oniyasha unleashed his blood demon art. His armor cracked and bled as crimson mist poured from his wounds, coalescing into armored soldiers made of blood and bone. Ghostly oni-warriors crawled from the shadows, each wielding spectral weapons.
"Fight my army, then!" Oniyasha thundered.
They surged toward Shinobu in a wave. Their footsteps crushed roots and tore through trees. Shinobu's eyes narrowed. She leapt down from her perch, her small frame weaving between the phantoms. Her blade flickered, stabbing, slicing, and stabbing again. Each strike was impossibly fast, her movements too sharp to follow.
Her sword left no wide cuts—only needle-thin thrusts, precise and surgical. Within seconds, the ghostly soldiers convulsed, their forms collapsing as poison corroded their essence.
Oniyasha watched, his grin faltering.
'What the hell? What kind of Demon slayer is this?'
Shinobu landed lightly before him, adjusting her grip. Her voice was calm, almost gentle.
"I have slain demons stronger than you."
His rage boiled over. He charged again, his odachi swinging in a wide horizontal arc. The sheer force split trees in half, the shockwave shredding leaves into dust.
Shinobu darted forward instead of back, sprinting under the blade. She moved so fast she seemed to vanish between steps, the forest erupting behind her. In the span of a heartbeat, she was at his chest.
"Dance of the Butterfly—True Flutter."
Her blade stabbed seven times in rapid succession, each strike plunging into the gaps of his armor before she flipped away, landing gracefully.
Oniyasha froze, his chest heaving. Then—his muscles swelled, forcing the poison from his bloodstream as his regenerative powers roared to life.
"Futile," he growled. "Your poison is nothing against my blood, girl."
Shinobu's expression didn't change, but her eyes narrowed slightly. "We'll see."
Minutes turned to what felt like hours. Oniyasha's onslaught was relentless, every swing of his odachi devastating, tearing the forest apart. Shinobu met him with grace and precision, her speed the only thing keeping her alive. She darted between roots, branches, and shattered trunks, her movements unpredictable, her blade always aiming for his weak spots.
But Oniyasha was not just strong—he was cunning. With each clash, he began anticipating her rhythm, adjusting his swings. The ground beneath them was cratered and scarred, the air filled with dust and blood.
Finally, one of his strikes grazed her haori, tearing it open at the shoulder. Shinobu landed hard, her breathing sharper than before.
Oniyasha sneered. "You're fast, girl, but even butterflies tire."
He raised his sword, crimson aura blazing. "Now die."
Shinobu's grip tightened. Her body screamed in pain, but her eyes flicked back—just once—to the place she hid Douma. That single glance steeled her heart.
'I can't die here.'
She inhaled deeply, her breathing steadying into perfect rhythm. Her small frame seemed to vanish into the forest's shadow.
'Because I have something to protect.'
As Oniyasha brought his blade down, Shinobu launched herself upward, her figure twisting in the air. Her sword glinted as she spun past him, stabbing into the side of his neck.
"Wisteria… Compound: Hundredfold!"
Her blade pulsed with venom, dozens of toxins flooding into him at once. The demon general staggered, his face contorting in agony. The veins in his body bulged black, his muscles spasming violently.
Still—he did not fall.
"IMPOSSIBLE!" he bellowed, clawing at his neck. His body regenerated even as the poison tried to tear it apart. He looked at her, fury blazing in his eyes. "No insect will kill me!"
Shinobu landed before him, her chest heaving. She smiled thinly.
"You're right. Not kill…" Her voice dropped. "...but delay."
Oniyasha's eyes widened—just as a faint groan echoed from behind her.
Under the dirt, a heavy presence surged like a rising tide, filling the forest with suffocating pressure.
The moment Oniyasha felt it, his instincts screamed. Whatever was hidden there was dangerous. His sneer faltered.
Shinobu raised her blade again, unwavering.
"You won't touch him. Not while I breathe."
Oniyasha roared, torn between fury and unease, his massive form trembling under the poison's assault. The forest quaked as the two forces—demon and Hashira—prepared to clash once more.