Wands and Wisteria(Demon Slayer/Harry Potter)

The thing about poisons, Shinobu mused to herself, was that they weren’t just random collections of dangerous things thrown together. They were an art; meticulous, balanced, deadly art. Every toxin, every root, every extract had a purpose, a harmony. Ever since she’d begun using poison to make up for the strength her slender arms lacked, she’d had to become part pharmacist, part chemist, and part artist. Every batch was an experiment, every drop a weapon honed for demons alone.

Wisteria, of course, was always the base.

It was a beautiful flower, soft and delicate, the kind that people wove into garlands and festival decorations. But beneath that beauty was pure venom to a demon. Wisteria could be used in countless ways—dried and crushed into powder, mashed into paste, soaked into a concentrated tincture. Its versatility made it perfect for her craft. No one truly understood why demons reacted so violently to it, but they did. Their skin blackened, their flesh burned, their regeneration halted like a candle snuffed out. Wisteria alone could wound them. But wounding was not enough.

No, to kill them quickly—and sometimes not so quickly—she needed more.

Fugu venom, drawn carefully from pufferfish glands. Mamushi viper toxin, its proteins delicate yet devastating. Crushed Asian giant hornets, their bodies potent with natural neurotoxins. Water hemlock, beautiful and merciless. Each ingredient lethal to humans, but in the right ratios, deadly even to creatures that laughed at dismemberment. The trick was knowing how they reacted together; how one dulled the burn while another amplified it, how too much could cause the mixture to spoil, and how the exact balance could mean the difference between a painless death and one of exquisite suffering.

Shinobu wasn’t cruel. 

At least, not always.

If the demon was newly turned, still trembling and half-mad with hunger, she believed in mercy. Those ones died gently—well, as gently as poison could allow. Their blood would boil and their bodies would convulse, but they would pass into unconsciousness before realizing how bad it truly was. 

But for the others… the ones who had lived too long, who had enjoyed the slaughter of humans, who smiled through the screams of children, those were reserved for her special mixtures. She had crafted poisons so vile that they made demons vomit themselves to death, their stomachs dissolving as wisteria-laced bile filled their throats. Others melted their lungs from within, leaving them gasping for air that would never come, the wisteria ensuring no regeneration could save them.

Shinobu’s lips curved slightly at the thought. The Demon Slayer Corps might call her methods unorthodox, but they worked.

Still, her mastery hadn’t come easily. Few in Japan were willing to teach her. Poisoners were secretive, paranoid folk—afraid she’d report them to the authorities, or worse, use their own craft against them. So she had taught herself. Through trial. Through error. Through pain. There had been nights she could barely breathe, her hands trembling from her own mixtures gone wrong. Once, she’d burned her lungs so badly she couldn’t speak for a week. The others had joked she’d die from her experiments long before any demon got the chance.

Now, years later, Shinobu Kochō stood as the Insect Hashira. And her poisons were legendary.

Her workshop reflected her discipline: clean, sterile, well-ventilated. The faint smell of alcohol and crushed herbs lingered in the air. Every vial was labeled, every pestle spotless. A cloth mask covered her mouth and nose as she stirred a faintly glowing liquid in a glass bowl, the fumes rising in delicate, shimmering trails. Outside, the others in the Butterfly Mansion knew better than to enter this wing when Shinobu was at work. The last time someone had interrupted her, she’d nearly gassed the entire corridor.

Knock. Knock. Knock.

Unless, of course, it was an emergency.

“Do not enter,” she said calmly, her voice muffled by her mask. “What is it, Aoi?”

She didn’t need to guess. Shinobu had learned to recognize her attendants by their knock. Kanoe knocked in slow, deliberate threes. Sumi, Kiyo, and Naho knocked together, like a tiny stampede at the door. But Aoi? Aoi’s knock was hesitant, soft, like she wasn’t sure she should be there at all.

“Mistress Shinobu,” Aoi’s muffled voice came through the door. “This isn’t quite an emergency, but… something strange has happened.”

Shinobu sighed quietly, setting down her glass rod and pulling down her mask. Her violet eyes flicked toward the door, curiosity glinting just beneath the usual calm.

Well, it was broad daylight, so that instantly ruled out a demon attack. That narrowed things down quite a bit. If a Slayer had been injured and needed medical attention, Aoi would’ve said so right away, and depending on the severity, she or the girls would’ve handled it themselves. The fact that Aoi hadn’t used the word emergency meant it wasn’t life or death.

So what could it be this time?

“What is it?” Shinobu asked, setting aside her pestle and straightening.

“Kanao has brought a dying wolf home.”

There was a long pause.

“…Kanao has what?”

“It’s a fairly big wolf,” Aoi continued, sounding uncertain even as she tried to explain. “And it’s bleeding quite badly. I think she wants you to help? I asked if she wanted me to call you, and she flipped her coin and said no, but she’s still standing there with it, and… well, you know how she is.”

Ah. Yes. Shinobu did know how she was.

She adored Kanao, truly she did, but the girl was a mystery wrapped in silk and silence. After all these years, after countless lessons, gentle encouragements, and not-so-gentle scoldings, Kanao still relied on that coin Kanae had given her to make decisions. Heads or tails: her entire world determined by a single flip of fate. It was charming in its way… and endlessly frustrating.

It had been a genuine shock when Kanao had decided to join the Demon Slayer Corps, and an even bigger one when she’d passed the Final Selection. A part of Shinobu had always worried that the girl hadn’t chosen that path for herself, that she’d done it simply because she’d seen her and Kanae do it first. Because she thought she had to, to belong. And while Kanao’s skill and determination spoke for themselves, there were still moments like this that made Shinobu question whether the girl’s coin dictated her heart.

Still… life in the Butterfly Mansion was rarely dull thanks to her.

You wouldn’t think a girl who only spoke in coin tosses and half-sentences could cause so much chaos, but somehow, Kanao managed.

Shinobu sighed softly and began tidying up her workspace. She covered every bowl, vial, and beaker, making sure none of the toxins she’d been using could evaporate or spill. Then she scrubbed her hands thoroughly at the basin until the sting of the alcohol solution faded from her skin—one could never be too careful. Poison didn’t forgive carelessness. She’d learned that the hard way, and so had the poor girls in the mansion the one time she’d forgotten to change out of her contaminated clothing.

Once her hands were clean, she carefully removed her mask and haori, placing them in the bin reserved for contaminated materials. Her uniform followed soon after. If she’d had the time, she would have bathed and washed her hair—poisonous residue clung like an unwanted perfume—but this sounded urgent enough to skip the ritual.

Fortunately, she was always prepared. A neatly folded uniform and butterfly-patterned haori waited outside the door, as they always did, thanks to Aoi. She slipped into them quickly, adjusted her hair, and took one last glance around her spotless laboratory before stepping out.

As soon as Shinobu stepped into the courtyard, she immediately understood what Aoi had meant — and, for once, the girl hadn’t been exaggerating.

There, standing in the middle of the wooden veranda as if this were the most normal thing in the world, was Kanao Tsuyuri. Serene, silent, unbothered… and beside her lay the biggest wolf Shinobu had ever seen in her life.

Not just large — enormous. Its body stretched nearly the length of a tatami mat, its fur a tangled, matted mess of grey and white streaked with red. Even lying down, the creature dwarfed Kanao, and Shinobu was fairly certain that if it ever stood on its hind legs, it would loom over her like a bear.

But right now, the massive beast was doing nothing but bleeding. Profusely. Onto her very nice courtyard.

Lovely.

“Hello, Kanao,” she said, her voice calm and lilting, though she couldn’t quite keep the sigh from creeping into her tone. She smiled, because that was what one did around Kanao. Sometimes a smile was the only way to coax a reaction out of the girl.

Kanao’s blank expression flickered, just for a moment, softening into the faintest hint of brightness. That alone made Shinobu’s smile deepen slightly.

“You’ve brought quite a mess here today, huh?”

Kanao blinked at her, reached into her pocket, and produced her coin.

Of course.

She flipped it into the air with practiced precision, eyes following its spin until it landed in her palm. Heads. Kanao looked up, as earnest as ever, and said in her quiet, lilting tone, “Yes.”

Shinobu let out an amused huff through her nose and gently patted the girl’s head, her fingers brushing through the dark hair. “Let’s see what you’ve brought me, then.”

She knelt down beside the creature, her smile fading as she got a better look. The wolf was still breathing — shallow, uneven, but breathing — which was something. But its condition was dire. Whole chunks of its flesh were missing, and blood ran freely from deep, ragged gashes, pooling darkly against the wood. It was a wonder it had survived long enough for Kanao to drag it back here at all.

Speaking of which… how had she managed to drag this monster halfway across the grounds? The thing must’ve weighed as much as three grown men. Shinobu decided she’d ask later, assuming the wolf survived long enough to make the conversation relevant.

For now, she focused on its wounds.

They were peculiar. Not clean like a blade cut, nor jagged like an animal bite. No, these wounds were something else — deep slashes, four parallel lines across the body, spaced with a precision that no wild beast could manage. The puncture wounds along the ribs, the missing chunks of flesh — all of it told a very specific story.

Her brow furrowed as she leaned closer, her sharp eyes tracing the pattern of injuries. A faint scent clung to the wolf’s fur, too subtle for anyone but a Hashira to notice — a metallic tang beneath the blood, tainted with something rancid, something wrong.

She knew that smell.

She had spent her entire life studying it. 

Hunting it. 

Killing it.

“...These wounds…” she murmured, her hand hovering over the wolf’s fur. “The depth, the spacing, the tearing…”

It clicked.

Her expression hardened, and when she spoke again, her voice was soft — but laced with iron certainty.

“This wolf was attacked by a demon.”

The words slipped from Shinobu’s lips like frost, coating the air between them in an uncomfortable stillness. Even the wind through the trees seemed to hesitate, as if the world itself understood the weight of what she had just said.

Kanao blinked once, her expression unreadable as always.

“Kanao,” Shinobu said slowly, standing from where she had knelt beside the wounded beast. “Where did you find this?”

The girl didn’t speak—of course she didn’t. She simply lifted a pale hand and pointed toward the tree line beyond the courtyard, her coin glinting faintly in the sunlight.

Shinobu followed the direction of her gesture and felt a sharp pang of unease twist in her gut.

The woods. 

Their woods.

That wasn’t possible.

The Butterfly Mansion’s forest was lined with wisteria trees planted generations ago, each one carefully maintained to ensure no demon could ever come near. The flowers bloomed in layers of protection, thick rows of purple sentinels that formed an invisible barrier for at least a mile in every direction.

For a demon to make it through that much wisteria…

Her hand unconsciously drifted toward her sword.

The mere idea that a demon could come so close to her home almost made her apoplectic with rage.

Had someone removed the flowers? Burned them? It was very rare, but some humans would sacrifice the lives of others to keep themselves alive for just another day, as long as they led the demon to more bountiful prey. She didn't want to believe that demons could be so close to her home…

And yet, the evidence was bleeding out on her floor.

Her eyes went back to the wolf. It was still alive, though barely, its chest rising and falling in a shallow, shaky rhythm. A fighter’s breath. The sheer will it must have taken to make it here, to Kanao of all people, was staggering.

But the question clawed at her mind.

Why a wolf?

Demons didn’t normally hunt animals unless they were fresh and desperate. Demons who had just turned would realize that all other foods, and even the raw flesh of animals, would taste like rot in their mouth upon turning. Human flesh was their obsession. For one to attack a wolf—especially this deep in the wilderness—suggested that the demons were new, which was good, because it likely meant that they didn’t have a Blood Demon Art yet.

She sighed softly, pushing her thoughts aside for now. There would be time to unravel the mystery later. For the moment, there was only one task that mattered.

“Well then,” she said quietly, her voice returning to that calm, lilting tone Kanao knew so well. “If you’ve brought me a patient, it wouldn’t do to let it die on my floor, would it?”

Kanao shook her head.

A small smile touched Shinobu’s lips as she rolled up her sleeves and called back toward the hall. “Aoi! Bring me the sutures, disinfectant, and two basins of water—quickly! And some towels!”

Then, glancing at Kanao again, she added more softly, “You did well, Kanao. Truly. Now let’s see if we can save your new friend.”

The girl nodded, expression calm, but Shinobu could see it; the faintest flicker of relief in her eyes.

As Shinobu knelt once more beside the wounded creature, she couldn’t shake the lingering thought that whispered at the back of her mind:

If a demon was hiding in these woods…it was now a danger to her girls. So she had to find them quickly, and make sure that none of them escaped to tell the tale.

_______________________________________

Human medicine, Shinobu was quickly realizing, could be adjusted for animals with only minor changes,  though some allowances had to be made. Wolves, after all, bled and breathed and hurt in all the same ways humans did. Their bodies simply demanded more care in how one handled the dosage, the stitching, the pressure.

She began by cleaning the wounds thoroughly. Buckets of warm water mixed with antiseptic herbs — a blend of Shiunkō ointment, crushed calendula, and a touch of Shinsen taitsukō — were poured slowly over the worst gashes, the liquid hissing faintly as it touched exposed flesh. The smell was sharp and floral, cutting through the metallic tang of blood.

The wolf stirred when water hit its side, a low rumble of pain vibrating through its chest. Shinobu murmured softly, her tone the same one she used for frightened patients. “Shh. Easy now. I’m not your enemy.”

It stilled again, trembling under her touch but making no move to bite. That alone was a small miracle.

She pressed linen cloths to each wound to stop the bleeding before carefully packing them with a medicinal paste — the same formula she used for demon slayers whose flesh had been torn or burned by demon claws. Dried wisteria acted as both disinfectant and deterrent to any lingering effects from the touch of a demon, while a mix of powdered herbs — mountain sage for inflammation, and mugwort to dull pain — would slow infection and promote healing.

Her hands were steady, practiced. She stitched where she could, fine white threads pulling flesh together in clean, minimal lines. For the deeper wounds, where stitching would do more harm than good, she layered soft pads of medicated gauze and secured them tightly with white cloth strips. By the time she finished, the wolf was bound like a soldier after battle, wrapped in her careful, deliberate handiwork.

It woke several times during the procedure — a sudden twitch, a half-hearted growl, a flash of yellow eyes — but never once did it strike. It only whined softly, watching her with a strange, weary intelligence, as though it somehow knew she was trying to help.

“That’s it,” she said, giving a small smile. “You’re quite the polite patient, even more so than some of my fellow slayers. Some of them wouldn't be so still as I stitched them up. ”

Kanao sat quietly nearby, holding a basin of water and handing her clean towels when needed. She watched every movement with her usual quiet attentiveness. It was the same way she had learned the basics of Flower Breathing from Kanae, just watching her elder sister as she practiced.

When it was done, Shinobu sat back on her heels, wiping her hands clean. The wolf’s breathing had evened out, its chest rising and falling in slow rhythm. She could feel its pulse, faint but stable, under her fingertips. It would live.

“If we end up with a pet wolf,” she said with a smile, glancing at Kanao, “I won’t complain.”

______________________________________________________

By the time the sun dipped low, painting the courtyard in soft amber light, Shinobu’s mind had already shifted from healer to hunter.

She called Aoi and Kanao together under the veranda as twilight deepened. The scent of wisteria drifted faintly on the breeze, calm and deceptive.

“Aoi. Kanao. I’m going into the woods tonight. Do you know why?”

Aoi hesitated, wringing her hands slightly. “Because of the wolf, right? You think there’s… something out there?”

“Yes.” Shinobu folded her arms, her expression calm but her tone sharp with focus. “The wolf was attacked by a demon, possibly multiple, with how many wounds there were. Kanao doesn’t wander far when she takes her walks, which means a demon has breached the outer perimeter of our wisteria fields.”

Aoi frowned. “But… even if that’s true, the forest’s covered in wisteria for miles. It shouldn’t be possible.”

“The wisteria grows thick for a mile, perhaps two,” Shinobu explained. “Beyond that, there’s open forest which is wild and unprotected. If a demon is lingering there, it could ambush us if we have to leave the mansion at night. I’d rather deal with it now, on my terms, than wait for it to decide when to strike.”

Her eyes shifted to Kanao. “You’ll stay here. Watch over the mansion, and the wolf. I don’t expect any demon to come this close, but…” Her tone darkened slightly. “Some are strong enough to push through the effects of wisteria. Those who’ve consumed many humans, or the ones that serve directly under Muzan, might not be repelled by it at all.”

Like the Upper Moons.

The thought was a blade twisting behind her smile. She didn’t truly believe one of the Upper Ranks would be skulking so close to her home, but she had long since learned that disbelief was a luxury she could not afford.

Kanae had once thought the same, too.

Breathe in. Calm yourself, Shinobu. Let it out. Smile.

The soft, practiced mask slipped easily back into place.

“I’ll handle it tonight,” she said lightly, as though discussing a simple errand. “If I haven’t returned by sunrise, assume I’ve been killed and contact Lord Ubuyashiki using the ravens. Under no circumstances are either of you to enter the woods. Is that clear?”

Both girls nodded, though Aoi’s face had gone pale.

Shinobu turned to her next, her gaze gentle but firm. “Aoi. I know fighting isn’t your strength, and I don’t want you taking unnecessary risks. But if — if — the worst happens and the mansion is breached, I need you to protect the girls. No matter what.”

Aoi looked down, her fists tightening at her sides. She wasn’t a coward, far from it, but Shinobu knew the terror that lingered behind those eyes. Aoi had survived Final Selection by the narrowest margin imaginable, and the trauma had never fully left her. She’d chosen to heal instead of fight, a decision Shinobu respected deeply.

It was, in truth, the smarter path.

Still, in times like this, courage was not a luxury.

“I sincerely hope I’m wrong,” Shinobu said softly, her lips curling into that delicate, practiced smile that always made her look so calm and harmless. “But if I’m not, if something does come, I trust you’ll do what needs to be done.”

Aoi’s throat bobbed as she swallowed, her fingers twisting at her apron. “Y-yes, Lady Shinobu.”

“Good,” Shinobu replied, her voice light as ever. “It’s likely nothing serious, but it’s best to be prepared.” She let her tone soften again, a careful balm to the tension in the air. “Eat dinner soon, and please don’t let the girls bother the wolf. It’s still a wild creature. I’d rather not have to stitch up anyone else tonight.”

“Understood, Lady Shinobu.”

“Goodbye,” Kanao murmured quietly, her tone as even as always, though her eyes lingered on her mentor longer than usual.

Shinobu gave one last reassuring smile, then turned toward the dark wall of trees beyond the courtyard. The light of the setting sun bled across her haori, turning the lilac and white of her butterfly wings into a wash of crimson and shadow. Her sandals whispered against the dirt path as she walked, each step steady and unhurried.

But as soon as the mansion was behind her, that calm smile changed. It sharpened, going from a show of kindness to one of teeth.

Her pulse quickened, but not from fear. Excitement.

“Demons,” she whispered under her breath, the word rolling off her tongue like a promise. “How bold of you.”

Her hand drifted to the hilt of her blade, fingers brushing the smooth lacquered sheath — her beloved weapon, filled with venom potent enough to melt through flesh and bone.

“Imagine it,” she continued softly, her tone lilting, almost playful. “Coming all this way… past the forest, facing off the wisteria… to challenge me. How very brave.”

The forest loomed ahead, dark and silent, the last slivers of daylight dying behind her. She tilted her head slightly, her eyes narrowing, voice dropping to a quiet murmur that was half amusement, half threat.

“Don’t worry,” she said, her smile curving into something cold and beautiful. “If death is what you came looking for… I’ll make sure you get it.”

And with that, Shinobu stepped into the forest, the evening swallowing her whole, like a whisper of perfume before the strike of poison.

_______________________________________________

She followed the trail the wolf had left throughout the woods. Big blotches of dark blood speckled the narrow path and stained the pale wisteria petals that overarched it; tufts of fur snagged on brambles like small, dark flags. The blood led away from the mansion for nearly five miles, winding into a pocket of woodland where the trees grew close and the underbrush thinned. 

That was the good news: whatever had attacked the wolf hadn’t crossed the protective ring of wisteria around the Butterfly Mansion. The animal had managed to find safety in their scent and thorns, and whatever pursued it had given up the chase where the flowers began to fall.

The bad news sat below her. Five demons, she counted without moving a muscle. They didn’t look like new or wild demons, not the scavengers you found near villages. These ones spoke to one another with a practised, civilized cadence, their voices sounding almost human as they spoke. Their clothes were tidy instead of torn; clean kimonos and yukata’s, scarves, things meant to pass in human markets, but the care with which they dressed also underlined how long they had been living as monsters. Age in demons shows itself in manners as much as in brutality. The longer they’d been around, the more taste they cultivated for disguises, for the petty courtesies of whatever humanity they stole.

How many people have you eaten? Shinobu thought, cold and precise. How many homes emptied, how many mothers left with empty arms? 

The mental arithmetic made her lips tighten. Tonight they’d pay for what they took. 

Did you know that demons carry a signature smell? The tang of old blood and rot layered over something metallic, like dried iron and fungus. Even those who attempted to mask it with perfumes and lotions never quite banished that base note. It clung to their skin, to their breath, to the hems of their clothes. These five didn’t bother pretending. The stink rolled off them in waves, thick and confident. It made the hairs along her arms rise.

She watched them from the upper limbs of the trees, perched among branches where the shadows and leaves made a perfect hiding spot. It was second nature to her to use the trees: humans and demons rarely look up, and the forest offered routes that made no sounds beneath a light foot like hers. 

A demon, arrogant and clever though it might be, would not expect a Slayer above him; their assumptions worked in her favor. They heard the occasional snapped twig and explained it away as wind, in the same way a human would excuse the sounds of a demon as a stray animal. How handy for her.

They were also arguing, which helped to further distract them.

“How the hell did you fools lose him?!” the tallest one snapped—red-eyed, lips still smeared with blood from a recent meal. He jabbed a finger at the others like a blade.

“You told us he was a human! You never mentioned he could do his own version of Blood Demon Art!” hissed a woman with a voice like broken glass. “There was fire and water and ice and explosions! If it wasn’t for our regeneration, we’d be dead. I had to eat three humans just to recover! He got away, and we had to stop when we smelled the wisteria!”

Shinobu’s grip tightened on the sword at her hip at the casual throwaway mention of three human lives. But the other words intrigued her.

“It’s kind of funny, though,” the youngest—boyish, his flesh still looking alive around the eyes—snickered. “All those nasty little tricks, and he still couldn’t kill us. Demon Slayers do a better job of it—”

“Don’t talk about them!” cut in a white-haired one, sharp as ice. “Do you want to call their attention to us somehow?!”

Too late for that, Shinobu thought quietly. 

“Stop acting like they’re ghosts,” a long-haired demon said, fingers toying with a broken knife as if it were a toy. “In case you forget, we are the monsters now.”

She threaded her breath with the smell of wisteria and blood, felt the old, steady thrill of the hunt settle in the bones, and began to move—down, through shadow, along a limb that led toward the trail’s end and the little knot of monsters who had made the mistake of speaking too loudly in the dark.

“Well, if we don’t find that man and kill him soon, we won’t be anything soon!” the tall demon snapped, voice rising. “You know who gave us this mission. The only reason one of the Twelve Moons isn’t here is because we were the closest to the target. We were promised more of Master’s blood if we succeeded, yes, but the punishment for failure…” His words trailed off into a shiver. “It will be unimaginable. We must find the Onmyōji before the sun rises again, or we’re all doomed!”

Master’s blood.

Shinobu’s breath caught. So he sent them here directly.

The thought iced her veins for half a second, then her pulse steadied.

 Muzan Kibutsuji.

The name alone was enough to make her smile—tight and humorless. If the King of Demons saw fit to personally send five of his own demons to take out a threat, then as a Hashira, it was her duty to find out everything about whatever it was that the Demon King wanted killed.

Her hand loosened around her blade, and she moved.

To the demons, it must have seemed like she dropped from nowhere—one blink, and a butterfly-shaped shadow was suddenly in their midst. A faint whisper of air was the only warning before she landed among them, blade glinting in the moonlight.

By the time the first one turned its head, she was already inside their circle.

Her sword moved faster than the eye could track; one precise slash across the young one’s face, the blade barely grazing yet leaving a streak of red that hissed as wisteria poison seeped in. The white-haired demon beside him jerked back far too late—her follow-up cut traced across his cheekbone and jaw, drawing a burning line.

The long-haired demon lunged from behind with a snarl, claws whistling through the air. Shinobu twisted her body, feeling the rush of wind scrape past her back, then pivoted on one foot and flipped over the demon’s swing. Midair, she stabbed downward three times, each strike a blur aimed at the creature’s arm, tendons splitting, dull red blood splattering across the dirt.

The female demon shrieked and charged, faster than the others, her fangs bared and her eyes wild. Shinobu didn’t retreat. She stepped in, blade flashing like a needle through silk, and thrust straight into her chest. The point sank deep, the smell of burning flesh mixing with the sweet scent of wisteria.

The demon froze mid-swing, choking on a gasp. Shinobu pulled the blade free and turned her back on her without looking, pointing her sword lazily toward the tall one—the one who had mentioned Muzan.

“You—you’re a Demon Slayer!” he stammered, stepping back.

“A Hashira,” Shinobu corrected softly, almost kindly. Her smile didn’t reach her eyes. “If we’re being exact.”

That was when the screaming began.

The ones she’d cut first clawed at their faces, flesh boiling and sloughing off like wax under a flame. The air filled with the wet sound of their regeneration failing, their cells trying to multiply and heal only to collapse under the toxin coursing through their blood.

The long-haired one fell to his knees, clutching the arm she’d stabbed. The skin bubbled and peeled, purple-black veins racing up to his neck as he wailed, his voice cracking into a child’s sobs.

The woman who’d taken a blade to the heart hit the ground next, her body convulsing, steam rising from her chest as her organs liquefied from within. Her final breath came out as a high, broken scream before she melted into a smoking heap of flesh.

Shinobu stood in the middle of it all, blade resting lightly against her shoulder, the soft smile never leaving her lips. The remaining demon stared in frozen horror, the stink of burning corruption filling the forest.

“Hey — look at me. Not them, me,” she said softly, using the tip of her blade to lift the demon’s chin and force his eyes to meet hers. “Don’t focus on the others. Right now, you’re very lucky, did you realise that?”

“I—I am?” he asked, voice small and hesitant.

“Of course you are. You’re alive, aren’t you?” she said, bright as a scalpel. “That means you still have a chance. Now, if you tell me what I want to know, you’ll live far longer than your friends over there. So tell me—” She leaned until they were almost nose to nose, the blade a quiet punctuation at his throat. “Why are you here in my woods?”

“M–my master sent me here!” the demon blurted, eyes flicking to her blade with a practised, guilty fear. “He called me several nights ago and told me of a foreigner who needed to be killed — a man from a distant land who was dangerous: an Onmyōji! I tracked him for days, and last night I, along with my group, ambushed him. He destroyed my upper body; it took hours to regenerate, so the others stepped in, but they lost him. That’s all I know, I swear!”

Onmyōji. The word landed in her mind like an ill-fitting key. It was the name of a court wizard — an official position once responsible for the creation of calendars, and supposedly magical rituals that were used to protect the court. Abolished in the Meiji era, it was the sort of term you would hear in history books, not in the forest, coming from the mouth of a demon. 

What would Muzan Kibutsuji want with what was essentially a bureaucrat, especially when there hadn’t been one for years?

“Your friends said some very interesting things before they died,” she said, voice flat as a report. “What did they mean by fire and ice and explosions? And how did this Onmyōji destroy your upper body?”

“He has some kind of Blood Demon Art, but he’s not one of us,” the demon explained, eyes never leaving the blade. “He had this stick with him, and whenever he shouted strange words the stick would do something. When we attacked him last night, he pointed it at me and said a word, and the next thing I knew it was almost daylight again.”

A human…with his own version of a Blood Demon Art? Just hearing those words out loud was so strange and unthinkable, that Shinobu could not tell, in that instant, whether that was good or bad, if she was being honest.

“Okay,” she said, slow and precise. “So if you were tasked with killing the Onmyōji, why did you attack a wolf last night?”

“Because the wolf is the Onmyōji!” the creature gasped. “That’s one of its abilities. My comrades said when they cornered him he turned into a wolf, fought them, then fled into the wisteria. Please, that’s all I know!”

It was almost like she heard glass shattering inside her skull as the demon spoke — the words snapping something in her brain.

Her blood went cold.

I left my Tsuguko and the girls in the mansion… with a man pretending to be a wolf.

A man who can set fire to things. A man who can make explosions. A man who—only the gods know what else he can do.

Her heart lurched. She needed to get back. Now.

“Thank you for the information,” she said curtly, voice clipped and polite.

Then she stabbed him in the eye.

The demon screamed, a high, wet, and animalistic sound, as the tip of her blade slid through his eyeball, the flesh already turning a deep, ugly purple from the poison spreading beneath the skin.

“W-why?! You said I could leave if I told you everything I know!” he shrieked, clutching his melting face.

“No,” Shinobu corrected softly, her voice calm, almost pleasant. “I said you’d live longer than your friends if you talked.” She leaned close, her tone dropping to a whisper. “And you did.”

She yanked her sword free, flicking the tainted blood aside with a sharp motion. “Goodbye, demon.”

The creature convulsed on the ground, its screams fading into wet gurgles as the poison consumed it from the inside out. Shinobu didn’t stay to watch. She was already moving — sprinting through the trees, her haori fluttering like butterfly wings in the dark.

Fear clawed at her throat, sharper than any demon’s talons. She could feel her heartbeat in her ears, faster, louder, urging her legs to move quicker than ever before.

Anyone who is an enemy of Muzan Kibutsuji should, in theory, be a friend of the Demon Slayers… she thought grimly. 

But I’m not gambling my girls’ lives on theory.

__________________________________________________________

It took her half an hour to make it back to the Butterfly Mansion — thirty long, breathless minutes spent sprinting through the treetops, the night air whipping against her face as she leapt from branch to branch. Each impact reverberated through her legs, her lungs burning, her mind racing even faster. She tried to keep a calm head — tried being the key word — forcing herself to believe that the creature would remember the kindness she’d shown it, the care she’d taken to heal it. But that didn’t stop the awful images flashing behind her eyes: Naho, Kiyo, and Sumi’s small, lifeless bodies torn apart by the snapping jaws of a “guest” they’d taken in.

By the time she reached the clearing, her heart was pounding so hard it hurt. But the sight that greeted her instantly loosened the vice around her chest.

Kanao and Aoi stood by the front path, moonlight silvering their faces. Kanao was gazing up at the sky, utterly calm as always, while Aoi stood beside her gripping a sword in both hands, her posture tense, her expression tight. The blade trembled faintly in her grip — the stance of someone ready to defend but praying they wouldn’t have to.

Both of them looked relieved when Shinobu appeared — well, Aoi did. Kanao simply turned her head, shifting her gaze from the moon to her mentor, a small, serene smile tugging at her lips.

“Mistress Shinobu!” Aoi said, voice spilling out in a rush. “Did everything go okay? Were there actually demons in the forest?”

“Yes,” Shinobu said, catching her breath but keeping her tone even. “Everything went fine. And yes, there were demons — but I took care of them.” Her eyes flicked past them toward the mansion. “Where are the girls?”

“Asleep,” Aoi replied quickly. “They don’t know what’s going on. We just told them you went out for a walk.”

“Good,” Shinobu said, nodding. “Good thinking.”

“And our… guest?” she asked after a pause.

“It’s doing fine,” Aoi said, though she hesitated slightly on the word it. “It hasn’t moved from the medbay. I made sure the girls stayed away.”

“Very good, Aoi. You’ve done wonderfully.”

This time, the smile she gave wasn’t one of her usual masks — not the sharp-edged one she wore to scare demons or the polite one she used for other Hashira. It was genuine, soft, and fleeting.

“Now, you and Kanao can go to bed,” she said gently. “I’ll check on our guest myself. It’s been a long day for both of you.”

Kanao only nodded and slipped away in silence, her coin glinting briefly in her hand as she turned. Aoi lingered for a moment, exhaustion visible in her posture, that mixture of tension and relief that came from knowing danger had passed but still feeling its shadow. Even without crossing swords with demons, the knowledge of their existence was enough to wear down anyone’s nerves.

And none of this will end, Shinobu thought darkly, until we kill Muzan Kibutsuji.

With that thought, she walked into the mansion, her sandals soft against the wooden floors. The medbay was quiet and clean, the air touched by the faint scent of herbs and moonlight streaming through the open window.

The wolf was awake.

It lay where she had left it, massive frame rising and falling with slow, steady breaths. Its fur glimmered faintly silver under the light, its bandaged wounds standing out starkly against the dark coat. Its golden eyes tracked her the moment she stepped inside.

“Hello,” she said softly, her tone careful and calm, like she was greeting a child or a wounded soldier. “I’m just coming to check on your wounds. Please don’t attack me.”

It wasn’t a lie. She would check the wounds…just not right away. First, she needed to get close, to gauge its temperament, its intelligence. A direct confrontation would be easy — she could cross the space and pin it before it even realized she’d moved — but unnecessary violence was sloppy.

If, by some miracle, this wolf turned out to be friend rather than foe… then she would prefer not to have to reopen every wound she had so carefully mended.

She stepped closer, her movements slow, deliberate — the soft padding of her sandals barely audible against the wooden floor. The wolf’s gaze followed her every step, pupils narrowing to thin slits.

“Easy,” Shinobu murmured, voice deceptively calm.

She reached out, resting one gentle hand lightly atop its head. The creature flinched but didn’t move. Its fur was coarse beneath her fingers, warm with life.

And in that same breath, Shinobu moved.

Her other hand flashed down in a blur, steel whispering free of its sheath. The tip of her Nichirin katana stopped a hair’s breadth from the wolf’s eye, glinting dangerously in the moonlight.

The wolf froze, a low growl rumbling in its chest. Its lips curled back, revealing rows of sharp, white teeth.

“I know what you are,” Shinobu said softly, her tone smooth as silk but cold as poison. “The demons, the creatures hunting you, told me before I killed them. They said you’re an Onmyōji, whatever that means.”

The growl deepened, vibrating against her palm.

“I didn’t think magic was real,” she continued evenly. “But then again, I spend my nights fighting monsters that eat people and do things straight out of old bedtime stories. So, I like to think I’ve got an open mind.”

The wolf’s hackles rose, its golden eyes glinting with something almost human — anger, or maybe fear.

“Stop pretending,” she said, tightening her grip on its head. Her tone never rose, but there was iron in it now. “We need to speak. The man who sent those things after you won’t stop. He’ll send more. So unless you want me to throw you back into the forest and let them finish what they started, I suggest you change into your human form and talk to me properly.”

For a heartbeat, there was only silence — the steady hum of cicadas outside, the wolf’s ragged breathing, her own pulse thudding quietly in her ears.

Then the growling stopped. The wolf blinked once, slowly, and met her gaze with unnerving intelligence.

She expected… something — wonderful, maybe. A swirl of mist, a flash of light, something fantastic — the sort of transformation she’d read about in children’s tales.

Instead, there was a simple, soft pop, like air being displaced.

And suddenly, a man sat on the bed where the wolf had been.

Shinobu’s blade wavered for just a moment.

He was nothing like she’d imagined. His hair was a vivid, fiery red, the kind that looked like it belonged to the sunset, not a living person,  and his eyes, a striking amber-gold, the same as the wolf’s, reflected the moonlight like molten metal. His face was strange, foreign. His nose was long and narrow, his features sharp, dotted faintly with small freckles that ran from his cheeks down his neck and hands. His clothes were stranger still: what looked like a kimono with no visible opening, layered over a shirt with a stiff collar — the kind worn by Western businessmen she’d seen passing through Tokyo.

“Please don’t kill me,” he croaked, raising his hands in weary surrender. His voice carried an accent she couldn’t place — clipped and lilting in odd places, every word deliberate but uneven.

Her eyes flicked over him, noting the details. The bandages she’d wrapped around his wolf form had remained, seamlessly repositioned across his chest and arms, as though reality itself had politely adjusted to his transformation.

Slowly, Shinobu sheathed her sword with a quiet click.

“You know,” she said, her voice returning to that calm, deceptively kind tone she used before killing demons, “even when I was threatening you, I wasn’t sure if I believed it.”

The man blinked, confused.

“I don’t often take demons at their word,” she continued, tilting her head with a faint smile. “But their story was too ridiculous to be a lie. For a good while, I thought you might just be an unusually clever wolf. I’ve met crows that could hold full conversations, after all.”

The man groaned and dragged his hands down his face, exhaling hard through his nose.

“Are you seriously telling me,” he said, his voice halfway between disbelief and exhaustion, “that I revealed myself because you were bluffing?”

Shinobu’s smile returned, the one she wore like armor, polite and harmless on the surface, sharp as a blade underneath.

“Yes,” she said lightly. “But to be fair… I’m a very good bluffer.”

He let out another groan and muttered something under his breath that she didn’t catch. Shinobu simply tilted her head, her expression that perfect mixture of amusement and quiet threat she had perfected over the years.
“Now,” she continued sweetly, “what are you exactly? The demons called you an Onmyōji, but that’s a government title. A bureaucratic one. And last I checked, officials don’t usually have the ability to turn into wolves.”

“I can’t tell you,” he said flatly, meeting her gaze. There was no hesitation in his tone this time, only fatigue. “It’s… not a matter of choice.”

“Oh, I think you can,” Shinobu replied, her voice lilting, casual — but her hand came to rest gently on the hilt of her sword. The movement was small, subtle, but the air in the room shifted instantly.

He sighed, shoulders slumping. “No, you don’t understand,” he said quietly. “It’s illegal for me to tell you. I mean that literally. I could be arrested — imprisoned — for the rest of my life just for explaining what I am. And as for you…” He hesitated, his yellow eyes flicking up to meet hers. “I don’t even know what they’d do to you. But it wouldn’t be good.”

Shinobu stared at him for a long, unblinking moment. When she finally spoke, her tone was low and steady — that terrifying calm she reserved for things she planned to dissect later.

“...You came into my home under false pretenses,” she said, every word measured and deliberate. “You could have changed into a man from the start, but you didn’t. You let us believe you were some wounded animal. You let my girls — my girls — walk near you.”

Her hand tightened on her sword. The smile didn’t leave her face, but her eyes turned cold.

“I used expensive medicines on you. Medicines that could have saved another Slayer’s life. You brought demons into my woods, near the only people I have left. I saved your life. You would’ve bled out in the dirt if my student hadn’t dragged you here.”

She leaned forward slightly, her voice dropping into something soft but deadly.

“You owe me your life. So the least you can do — the very least — is tell me why mine, and the lives of everyone under this roof, are in danger. And why the King of Demons himself is hunting you.”

The man said nothing. The silence stretched — taut as a wire between them. His golden eyes flicked down to the blade resting at her hip, then back to her face. Shinobu liked to think she was good at reading people — tone, breath, microexpression — but this man was an enigma. There was calculation behind his exhaustion, intelligence behind his fear.

Finally, after what felt like an eternity, he nodded once.

“…Alright,” he said quietly. “But once you know, once you hear the truth, you’ll start recontextualizing everything you know about your life, your leaders, and your government. Do you understand that?”

Shinobu didn’t blink. “Try me.”

He looked away, as though bracing himself. When he began to speak, his voice was low, weary, and heavy with the kind of truth that rewrites the world.

And as he went on, Shinobu’s expression barely changed,  but inside, she could feel it. The slow, creeping realization that everything she thought she understood about monsters, about magic, about the world itself, was about to come undone.

By the time he finished his first sentence, she already knew that this night was going to change everything.