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Chapter Text

The crisp air of the night was making Rengoku dizzy, among the blood loss he was experiencing. He could no longer see through his left eye anymore, his lost depth of vision working cruelly to his disadvantage. Dawn wouldn't break for another forty minutes. Could he stay on his feet for that long? A shiver ran down his spine as he looked at the monster standing before him. Akaza, with an ugly smug on his face, looked as good as new - like Kyojuro's slashes never had reached him.

It was so frustrating. Rengoku had hoped to buy some time, but even that was slipping out of his reach. Demon seemed to posses some kind of ability to read his movements, making his every attack predictible and easy to dodge. Crushing pain was becoming harder and harder to ignore, with ribs shattered Rengoku's breaths got shallow, dulling his slashes even further. In hopeless moments like these his resolve was crumbling, his father's harsh words sneaking right into his heart like a poison. Useless. Not talented. So why bother trying? 

He was out of options. He knew that.

From the moment he saw an Upper Rank Three arrive, he understood he wouldn't live to see the sunrise. But that was okay - he had already made peace with that thought. It was the risk every Hashira had to consider and fight despite that grim prospect. For it was an honour and the duty of the strong to protect the weak. He was sure his father onced believed the same, until one life too many slipped through his fingers. Rengoku clutched his sword tighter, because he was not letting anyone die tonight.

And no matter what, he would have his duty fulfilled.

*   *   *

Tanjiro gasped for air, his eyes snapping wide open. Still fighting for breath, he sat up in bed and wrapped his arms around his knees. One quick glance around was enough to assure him that he was no longer on the battlefield. The familiar scent of the Butterfly Estate soothed his nerves and his confusion finally began to fade. The room he was in was still and quiet - everything shrouded in the darkness of the night.

"Oh, you are finally up."

Tanjiro turned toward the window where the voice had come from. It was Zenitsu sitting on the sill, with a cup in hands and a strained look on his face. Dim light of the moon highlighted a dark circles under his eyes, giving him a ghost like quality. "You don't look too good Tanjiro, should I call Shinobu-san?" The red-haired boy shook his head, wanting to ask Zenitsu the same thing. It looked like both of them were in pretty rough shape.

"No need. I just.. didn't sleep well."

It was true - every molecule of his body was screaming from exhaustion, like he hadn't got any shut-eye at all. But the worst were not his injuries, at least not the ones of flesh. The same nightmare kept replaying in his head over and over again, only just now releasing him from it's tormenting grip. "Wait," he asked quietly, "how long was I asleep?"  Zenitsu tensed slightly, looking at him with a sense of pity.

"About three days. You lost a lot of blood during... our last mission. You passed out cold."

Last mission...

So it had been three days already...?

Silence settled between them, but neither of them dared to disturb it. The weight of guilt and shame hanged over Tanjiro as he was recalling events of the past days.

Events that should never have happened in the first place.

He clenched the bed sheets, knuckles turning as white as cloth beneath his grip.

Why did it have to happen?

Everything had been going so well that night - first time in a long while. Thanks to Rengoku-san's quick thinking and strategic sense, they were able to make the best of their strong suits. Together, they fought - slashing the demon's body mercilessly and giving aid to those in need. Tanjiro had pushed past the despair of watching his family die over and over again, because he never doubted their ability to win against such a strong oponent - not when his mentor was around. And they did it, they really did, Lower Rank One was finally defeated! And Rengoku-san had saved everyone.

Yet nobody could have saved him.

"I... was unconscious when it all happened but Inosuke told me everything." Zenitsu began slowly, searching for the right words. "I can't even imagine what you must've felt, seeing it all unfold before your eyes. I'm sorry I couldn't be of any help." He lowered his head in shame.

How could Tanjiro ever be angry at Zenitsu if he himself couldn't do anything? His vision got blurry, tears stinging his eyes and threatening to spill. Oh, how he wished he could turn back time - to that moment when he was laying on the ground, with Rengoku-san's calming presence above him. He would've stopped the bleeding faster, he wouldn't have listened when Rengoku-san told him to stay still, he would've helped him, save him, save him from that back-breaking fate of...

"It's... not fair..." A small sob finally escaped his lips. "Every time I learn something new, I just see how much I still have to learn... It feels like no matter what I do, how hard I train... There is always an enemy one step ahead... I can't keep up and everyone has to protect me..." Tanjiro couldn't stop the words - it was as if a dam inside him had broken, releasing his deepest insecurieties. The strenght to fight these feelings left him as tears began to fall. "How am I supposed to look in the mirror, knowing what Rengoku-san had to do to protect us? How can I face his family and explain what happened?"

Tanjiro felt the bed shift beside him and as he shivered, a hand started to gently rub his back.

"I know how you feel, I really do..." Zenitsu voice was barely above a whisper. He did know - better than most - what it felt like to not be enough. Bringing comfort, on the other hand, was new to him. Sitting together with his friend on the bed, he couldn't help but feel guilty. It was always the other way around. As he was breaking down, it was Tanjiro's steady presence, helping him through the worst. Now, with Tanjiro shaking under his hand, Zenitsu realized it was his turn to say that everything would be okay.

But... would it be...?

For now, he decided to push the doubt aside. It wasn't about him - it was about Tanjiro. He would try to give back some of the hope he'd received countless of times before.

"Listen, from what I've heard, Rengoku-san was able to restrain himself, right? He didn't hurt you, or anyone else. The smell of blood in the air must've been unbearable since so many were injured, and yet..." Zenitsu's voice trembled as he spoke. "Maybe... Maybe Rengoku-san is like Nezuko in a way?" 

The look on Tanjiro's face was a mixture of bewilderment and causious hopefulness. 

"Do you... really think it's possible? It might just have been his last shreds of consciousness before he..."

Before he turned into demon.

"Well, I want it to be true." Zenitsu hesitated, his voice almost faltering as he looked up. "Don't you?"

*   *   *

His head was splitting in half in a way he didn't know was possible. Shivers were constantly running through his fiverish body, the hard ground underneath not giving any comfort. Rengoku couldn't even keep his eyes open, everything around him being uncharacteristically overwhelming.

There was something festering in his gut, and in his brain too; an all-consuming fire, violent and unforgiving. 

Was it... Anger?

Why was he angry? Had he always been feeling this way?

Sharp nails drew blood from his temples as he clutched at his head, desperate to make this ugly feeling stop. But it didn't. The more he tried to get to the bottom of it, the more restless he became.

He didn't know, he didn't remember a single thin-

A cold hand rested on his forehead. The touch alone dulled the pain, easing the fire inside him. Familiarity of the gesture softened his features. 

"I can see how much you are struggling, Kyojuro." 

That voice - he knew that voice! So soft, yet unwavering. The same...

"As your mother, it pains me to see you in such a state. But you must endure, you must move forward, as the lives of many still rest on your shoulders. Your appearance may have been altered, but your spirit remains unchanged."

The weight on his chest subsided, replaced with reassuring warmth.

"Set your heart ablaze, my son."

His eyes fluttered open, searching for his mother, but the only thing left of her was a fuzzy feeling. He looked around curiously, taking in his surroundings. The house was on the smaller side, paneled with obsidian-black wood. The fire of the irori danced on the polished surface, giving the room a sense of coziness. And yet, nothing about this place sparked any memories. 

Where was he?

As he pushed himself upright, something slipped from his forehead and landed on the floor with a soft splat. A wet cloth?

"My, my... it seems you've found your way to the land of the living."

Rengoku startled at the unknown voice, coming seemingly out of nowhere. Looking around, he spotted a short woman, sitting before what must have been an altar. She was an older lady, perhaps past her seventies, with an ash-white hair tied into a flawless bun. The sage-green kimono she wore was clearly well cared for, not a single thread out of place. There was something peaceful about her presence, which Rengoku found oddly calming. But what truly caught his attention were her pale, unfocused eyes. He wondered if she had any sight left.

"Ah, it appears that I have, but... what happened to me in the first place?" Rengoku tried to jog his memory once again, but he had no recollection of... pretty much anything. He could only remember his mother: her silky black hair, her ruby-red eyes and fragments of moments they shared. The image of them reading poetry, the faint scent of flowers from the garden... Just some flashes, here and there, lasting no more than a few seconds.

"Well, well... I went down the stream for some water before dawn, but when I returned, the door were open and the air inside felt... different. I called out, but all I heard was snoring." She giggled softly, covering her mouth with a trembling hand. "I followed the sound and found you there, burning like a hearth! I was so worried you wouldn't pull through, poor thing."

Rengoku listened intently. Something terrible had happened to him - of that, he was certain. Everything was shrouded in fog, but he was determined to uncover the truth, piece by piece. Straightening, he bowed low in her direction out of instinct.

"I understand. Please forgive me for the intrusion and for being a burden."

The smile never left her wrinkled face, as she shook her head gently.

"You are not a burden at all, young man. I'm glad you are feeling better. Now, now - after such a restless slumber, I'm sure you must be starving!"

Starving.

Oh, starving he was.

Woman set an onigiri and a bowl of steaming miso before him with surprising ease, her movements slow yet precise. The smell... was off somehow, but Rengoku didn't give it much thought. He picked up a piece of tofu with his chopsticks and put it into his mouth.

He regretted it instantly.

His body convulsed and retched, doing everything in its power to get the food out of his system. He spat the tofu back out.

"Look at that... A little too early for a meal, perhaps?" Moriyama tilted her head slightly.

"I-I'm so sorry! I don't know why I did that! I'm sure it's delicious, I just-" Rengoku's face flushed with embarrassment. He wished he could crawl into a hole and never come out.

"Don't worry about it at all, sweetheart." Her tone was kind, utterly unbothered by the incident. "A high fever can make food taste strange. My daughter used to experience it a lot when she was younger." Sensing Rengoku's discomfort, she gathered the dishes in a practiced manner. "Please, don't feel bad. I'm not angry."

He nodded, though he couldn't shake the feeling that there was more to it than a symptom of some illness. His body was clearly betraying him.

"My, my - where are my manners?" the woman said suddenly, a smile in her voice. "I got so excited to have a visitor that I forgot to introduce myself. I'm Moriyama Keiko. It's a pleasure to meet you."

"My name is..." Rengoku froze. "It's..."

Oh great. He couldn't even remember his own name.

"It's okay if you can't tell me, Demon Slayers can be quite secretive..." she chuckled under her breath.

"No, no, it's not that, I really can't remem- Wait." He stopped mid-sentence, blinking. "You said Demon Slayers?"

"You are one, aren't you? Not many people carry swords these days. And your uniform, the texture of it... " She lifted a hand, pointing just off to his side. "It's a rare fabric - extremely resilient to the elements, yet soft as silk to the touch. I've only ever known the Corps to use it."

Rengoku looked down at his outfit, examining it closely. It was stained with blood, yet the cloth itself remained completely intact.

Curious.

Moriyama reached into a nearby drawer, reatrieving a sword and a neatly folded haori. Rengoku's breath caught as he drew the blade. Metal reflected the fire from irori beautifully, bringing out it's fiery hue. It felt right in his hands - balanced, precise. Definitely a work of a skilled swordsmith. From the razor sharp edge of a blade to the carefully sculpted tsuba and steady hilt - everything screamed perfection.

It felt familiar. His.

To his surprise, knowledge resurfaced - snippets about the Demon Slayer Corps, their duties, their hierarchy, their Breathing Styles and a sense of community. It was like the information was always there, burried somewhere in his mind. 

"The Corps saved my family more times than I can count. For that, I will forever be grateful." The older woman placed her hands on the wooden floor, her forehead touching the floor as she bowed deeply in a saikeirei fashion. Rengoku got flustered by the gesture, lowering his gaze.

"I'm not worthy of your reverence, madam. My mind is nothing but a blank page as of now... I cannot even be certain that I belong to the Corps."

It was such a strange feeling for Rengoku - recalling all this information without any real connection to it. He looked at his blade again, as if it held some hidden knowledge just beyond his comprehension. He wondered if he had really used it to slay a-

Demon.

With a sharp gasp, the sword slipped from his grasp and clattered to the floor.

What was that just now? An eye, lurking in the sword like a beast hunting it's prey?

"Oh my, my... is everything alright?" Moriyama's voice was gentle, the kind that carried a mother's concern.

"Do... do you, by any chance, have a mirror?" 

"There should be one, yes. Give me a moment."

Woman began rummaging through one of the shelves on the other side of the room. When she felt a familiar oval shape under her hand, she hummed, satisfied, and handed it to him.

Rengoku opened the simple blue pocket mirror, praying that his assumption was just a trick of the light.

But there they were - two crimson eyes rimmed with gold, their white pupils narrow and sharp like slits, staring back at him. As his lip began to tremble under his own gaze, another unwanted feature revealed itself - a set of fangs, their sharpness rivaling that of his sword. 

It can't be...

On the left side where his lower lip ended, the blood-red mark began, shaped like a flame and running down toward his collar, the rest hidden beneath his uniform. He snapped the mirror shut with a loud clack.

It can't be real... can it?

"Is your reflection not to your liking? I didn't feel any scars or bruises when I was examining you."

"I just... don't recognize myself."

The weight of those words nearly broke him. When he'd looked into the mirror, he couldn't tell which qualities were truly his and which were merely the consequence of becoming a demon. Was his hair always this bright? What about the color of his eyes?

Amid the horrid feeling of no recognition and fear of what he had become, what struck him most was disappointment. In a mirror, he had hoped to find at least a trace of his mother's gentle eyes. Foolishly, Rengoku imagined that maybe - just maybe - he could find a piece of her in himself.

He was sinking deeper into the spiral when a touch on his forehead brought him back.

"Everything you've ever lost is right here. It's in a safe place, at hand's reach." Rengoku looked up at her face as she stood before him. Even though her vision was impaired, he felt bare under her knowing gaze. "Whatever you went through before you came here, I'm sure it left a mark - one way or another. Finding yourself again... It takes time. The kindness you give everyone..." she said gently, brushing his hair to the side, her smile softening.

"Find some for yourself as well."

But how...?

How could he be kind to... this?

To that creature staring back at him from the other side of the mirror?

Would she still say that - if she knew what he was?

"I can certainly try." He forced a weak smile as he handed the mirror back. Moriyama could tell he was not convinced. She truly wanted to help him, to offer the reassurance he so clearly needed.

"I want you to keep it."

"Keep it?" Rengoku's eyebrows shot up in surprise. He shook his head quickly, trying to return the gift back. "No, I couldn't-"

"Keep it." she said again, her tone determined and grip strong. "For the day when your reflection smiles back at you."

He looked at the small object he'd been given.

So that was what his mother had meant when she visited him in his dream.

Your appearance may have been altered, but your spirit remains unchanged.

It felt like a promise, one he desperately wanted to be true - that no matter what, deep inside, he was still himself. Whatever himself even meant at this point. Clenching the mirror tightly, he decided to believe.

He had to.

Chapter Text

Giyuu felt like his back was about to kill him. Kanzaburo, always the dependable one, had led him through all sorts of remote places - none of them offered a warm bed and roof over his head, of course. For the past few nights, he'd slept on damp moss somewhere deep in the forest, a place so quiet even wolves had forgotten it existed.

It was a miracle, truly, that he'd made it on time for today's Hashira meeting.

The crow shifted on his shoulder restlessly, trembling as usual. If Tomioka didn't know Kanzaburo so well, he might've thought the bird was misleading him on purpose - just to keep him on his toes. With a sigh, he untied a furoshiki tucked into his haori's sleeve. The cloth, patterned with waves and clouds, had been a gift from his master long ago. Now, too small to keep his rations there, was a perfect size for a handful of seeds for Kanzaburo. Crow perked up as Giyuu fished a few out and scattered them on his palm.

"Giyuu... so kind, so kind..." Kanzaburo chattered, nibbling eagerly at the treat.

The words tucked the corner of his lip ever so slightly.

Now that he was finally free from his duty, he had time for a visit. Tanjiro had awoken a few days ago, yet something always seemed to get in the way.

As he headed toward the Butterfly Mansion he passed a small sweets stall, appetizing aroma of red bean filling the air. He spared it a glance - the trays were piled high with taiyaki and sweet buns, steam gently hovering over them. A thought crossed Tomioka's mind as he wondered if Tanjiro had a sweet tooth. He quickly pushed it aside and kept walking.

Five minutes later, a paper-wrapped bundle of manjuu was in his possession.

The Butterfly Mansion was the same as always - quiet, with a faint scent of medicine lingering in the air. He spotted Aoi in the garden, her hands full of laundry, sunlight catching on the wet, white cloth.

"Oh, it's you, Tomioka-san," she noticed him as she reached for a clip. "Tanjiro is on the second floor - last room on the left."

He gave a short nod, quietly wondering if she possessed some kind of mind-reading ability. As he climbed the stairs, he began quietly rehearsing what to say.

I wanted to see how you're doing. So... how are you doing?  - Too awkward.

I'm happy you pulled through. Here, have some sweets. - Too forward.

I was just passing by and remembered you were at the Butterfly Mansion. - Too casual.

He halted just outside the room, hand hovering over the handle as second thoughts grew louder. He glanced at the paper packaging in his grip - the buns were still warm. 

Was this really okay? Could Tanjiro even eat sweets in his current condition? What if he does not, in fact, has a sweet tooth?

He almost turned on his heel, ready to pretend the whole thing had never happened - but stopped in his tracks. Aoi had already seen him; she'd tell Tanjiro, and then he'd have to explain why he'd left without a word.

And that sounded even worse.

He took a slow breath, closed his eyes and tightened his grip on the handle.

Now or never.

As the door slid open, Tomioka was greeted with a scream.

"Gonpachiro! Get - up! Get - up!"

Inosuke was on Tanjiro's bed, swinging his chipped swords wildly over his head. "We gotta train!"

"Stop bothering him already, you stupid boar head!" Zenitsu shouted, trying to pull him away - unsuccesfully. "And put those blades away before you kill someone!"

"Don't be so loud, please. There are other people in the mansion..." Tanjiro tried to mediate, but paused mid-sentence when he noticed the figure in the doorway. "Giyuu-san! You came!"

The banter halted. Three pairs of eyes were now curiously staring at Tomioka, making him awfully self-concious.

"I'll come back later." he muttered, already reaching for the door.

"No, no! It's fine!" Tanjiro said quickly, patting the spot beside him on the bed. "Please, stay with us!"

"Yeah, we don't bite!" Inosuke added, puffing steam through his mask. Zenitsu gave him an unimpressed look.

"That's so convincing, coming from you..."

A little hesitant, Tomioka stepped inside and joined them, settling awkwardly beside Tanjiro. The boy sniffed the air, his gaze landing on the paper bundle in Giyuu's hands.

"Is that manjuu?" 

Tomioka blinked, glancing down at the package. A quiet oh slipped from his lips as he remembered the forgotten sweets.

"I bought some on my way here. You can have it." 

"That's so kind of you, Giyuu-san - thank you!" Tanjiro's beamed, his smile widening as he peeked inside the wrapping. "Wow! And you bought so many!"

Tomioka's hands grew clammy as he subtly fidgeted with them. He had no idea how the boy could give praise so effortlessly. 

"Impossible!" Inosuke snatched the sweets from Tanjiro, lifting it above his head triumphantly. "You can't possibly eat them all alone!"

"You're right, let's eat them together!" Tanjiro clapped his hands, looking as unbothered as ever.

"No - hold on, Tanjiro," Zenitsu, on the other hand, looked very much bothered. "You don't have to humor him every time! It's your gift, not his."

Giyuu didn't speak up, but internally, he agreed.

"It's okay, Zenitsu. I don't mind. I think everything tastes better when you share it with friends."

"See, piss hair?" Inosuke stuck out his tongue, already bracing for his grand escape. "He said I can have 'em all!"

"He did NOT, in fact, say-" Zenitsu halted, a crackle of electricity sparking off his body. "WHO ARE YOU CALLING PISS HAIR, YOU ILLITERATE, THIEVING-"

He tore down the the hall after Inosuke, their arguing echoing through the mansion until it dissolved into the distance.

Tomioka glanced at Tanjiro. The scratches on the boy's face were healing nicely - similarly to the wound on his stomach, that's what Kocho had told him after the assembly.

Ah.

Right.

He should be the one to break the news, shouldn't he?

"Oyakata-sama held an assembly today," he started quietly. "It was about Rengoku."

Tanjiro's ears perked up immediately at the name.

"How was it?" 

"..."

Just say it.

"We settled on the official report for the mission. It states that Rengoku Kyojuro fell in a battle against an Upper Rank Three."

"What...?" Tanjiro's brows furrowed, as if he couldn't trust his own hearing. "That's not what happened - he didn't die-"

"You're right. He did not." Tomioka admitted, eyes dropping to the floor. "But for now, we have to pretend that he did."

Tanjiro pressed, conflicted, his composure slipping. "I- I know his condition is... troubling. But to put him in the grave while he's still breathing..." His lips trembled. "Why do such a thing...?"

"To protect the Corps. Imagine what would happen if word spread - that someone holding the position of a Hashira became a demon."

The Hashira were called the Pillars of the organization for a reason. With unbreakable willpower and exceptional swordsmanship, they stood as the ultimate symbol of the slayers' virtues.

It wasn't a secret that, throughout the Corps' long history, there had been swordsmen who turned - for one reason or another. It was never excused, never accepted, but it was a brutal reality of their line of work. Not everyone had a spirit strong enough to withstand despair, temptation, or sheer terrible luck. That was the unfortunate truth of being a human.

But a Hashira becoming a demon? Unthinkable.

Because if even a Hashira wasn't immune to the corruption, no one was.

It was better to die in a battle - even take their own life - than to shatter the illusion so many clung to. And for that, Giyuu couldn't see the position as something honorable. In his eyes, it was nothing but a curse - and what fate had been decided for Rengoku, despite his sacrifice, was the clearest example of that.

"And with that," Giyuu dug his nails into his palms, bracing himself. "The Hashira were ordered to find him..."

"They were? That's a huge relief!" Tanjiro exhaled shakily, a weight visibly lifting from his shoulders - far too excited to notice that Tomioka hadn't finished what he meant to say. "Just the other night, Zenitsu and I were talking about finding him ourselves. But with your help... we'll have a real chance!"

As Tanjiro's face brightened with hope, Tomioka couldn't find the courage to say the rest of the order.

"I remember the direction Rengoku-san fled. We can split the search to cover more ground. Inosuke and Zenitsu should leave the Butterfly Mansion next week, I'm gonna need around two more weeks of recovery, but after that - I will do my best!"

A knot started forming in Giyuu's stomach, tight and heavy. If there was an opportunity to correct Tanjiro - to say what would actually happen after they'd found Rengoku - it was gone for good. The room felt like it was shrinking around him, Tanjiro's enthusiastic planning only making it worse.

"I'll have to ask the other Hashira which areas they're searching so we don't doub-"

"Don't."

Tanjiro tilted his head, giving Giyuu a questioning look. But Tanjiro wasn't the only one surprised by his sudden interruption. 

He had to come up with something, and he had to do it fast.

"Don't... speak of any of it. Someone could overhear," he said, forcing his voice to remain even. "Only his family, you four, and the Hashira know the truth about Rengoku - and it has to stay that way. I... I'll ask them for you at the next meeting."

Tanjiro's eyes lingered on him a beat too long, searching for something. Giyuu felt his chest tighten, but the boy simply smiled. If he suspected anything - he did not tell.

"Okay! Let me know if you learn anything."

The floor creeked softly as Giyuu stood up from the bed. It was best to leave before he made the situation any worse.

"For now, you need to focus on resting. If you want to be of any help." 

"Will do!"

Giyuu was nearly out the door when Tanjiro spoke again - his voice quiet, almost pleading.

"Um... Rengoku-san acts a little different than usual, he might not even recognize you at first, but... It's still him. When you find him, please... Don't be too rough with him."

Don't say it.

"I won't. I promise."

The words stung on his tongue like poison. Why did he do that? What was it with him and keeping pledges that could change his life forever?

"Then I'm sure he will be in good hands," Tanjiro said softly, happy with that answer.

Giyuu nodded absently, thankful the boy couldn't see his face.

One look would have been enough to figure out the thought plaguing his mind.

How to be gentle with someone he was meant to kill?

* * *

Scorching heat was almost too much to bear for Tanjiro as he paced through the narrow roads. Sweat ran down his back and chest, making the bandages cling uncomfortably to his wound. Shinobu would lecture him relentlessly later - he was very well aware of that. Sneaking out of the Butterfly Estate with an injury not yet fully healed had been a terrible idea, and the consequences were catching up fast; with every larger movement, he could feel the wound tearing little by little.

Clearly, he wasn't in any condition to take on the task resting on his shoulders. Yet nothing could convince him to wait - the weight of the promise gnawed at him from the inside.

For Rengoku-san's sake, he kept repeating whenever his legs threatened to give way. Fortunately, the destination of his journey was close; Kaname had begun circling overhead.

Turning the last corner, Tanjiro stopped in his tracks - a painfully familiar silhouette stood in the distance. For a heartbeat, he almost let himself believe...

"You... must be Senjuro, right?" Tanjiro asked, walking up closer, breath uneven. The boy turned toward him, fingers tightening around his broom. The resemblance between the brothers was uncanny - the hair, the eyes... and yet, something about Senjuro was different. He carried a timidness his brother never had.

"I believe word has already reached you regarding the fate of Rengoku-sa- Rengoku Kyojuro." Tanjiro's fingers fidgeted with the hem of his haori as he forced himself to meet Senjuro's eyes. "He entrusted me with a message."

"A message... from my brother?"

Senjuro's gaze grew distant as he watched Tanjiro bow hesitantly, the words taking a moment to register. When they did, his eyes widened with realization. "Ah - yes, I've heard what happened. I would gladly listen to your story, but..." he faltered, his eyes flicking over Tanjiro with worry. "Are you feeling all right? You look like you are in pai-"

"STOP!"

The raspy voice cut through the street like a crack of a whip, making both boys jump. "Don't you dare bring the words of a traitor into this household! I don't want to hear it!"

There he stood - the head of the Rengoku family, Rengoku Shinjuro. Looking at the man, Tanjiro understood immediately who the brothers had taken after. 

But the eyes staring back at him were nothing like Kyojuro's.

Kyojuro's had been endlessly kind and reassuring, their warmth like a steady glow of an irori. The fire burning in his father's hardened gaze was the sort of flame that turned everything in its path to ash.

Seeing Rengoku's features on that man felt deeply wrong.

"Sir," Tanjiro began carefully, "I'm not sure if you are aware, but Kyojuro-san did what he had to do to sav-"

"Stupid excuses!"

Shinjuro's voice was rough as gravel. "If he were truly talented, none of that would have ever happened! I told him his efforts were useless - but he never listened! He just went out into the world swinging his sword with that laughable skill set of his - and look how he ended up!"

Spit flew as he slurred the words, waving a half-empty jug of sake in one hand. "For hundreds of years, our family held the title of Hashira with pride. None of them ever turned. And now, all that heritage - tainted by my worthless son!"

Tanjiro stood frozen in utter shock as he listened to that gut-wrenching tirade. But his disbelief quickly turned into anger - a kind of anger he rarely felt toward others.

"How can you even say such things?! Don't you have a heart?! Any empathy at all?!"

He stepped forward, hands trembling. 

People dealt with grief differently - that much he understood. Yet, the actions of a man before him felt far from grief.

It was a spiteful mockery.

"Everything he did - he did to save people! And he succeeded! Nobody was killed that night! You should be proud that your son selflessly gave up his humanity so others could live!" 

Rengoku's last wish echoed in his mind.

Please, tell my father that... I'm sorry. I know it's just a wish of a dead man now, but if there was only a way... I would give anything to turn back time, to the moment our family still... felt like one.

A sharp ache tugged at Tanjiro's heart as the meaning of those words sank in.

He couldn't imagine what it must have felt like - to come home and be met with violence or cold indifference from the person you held most dear. But Rengoku kept smiling, never letting his heart be broken.

No, Tanjiro realized, lowering his head.

Just never letting it show.

And against all odds...

Those last words - that final wish - had been meant for his disgraceful father.

That dream of becoming a family again still burned in him until the very end. 

Not everything was lost, Tanjiro reminded himself. Rengoku-san was still very much alive, just... different.

In the heat of the moment, he made a promise he wasn't sure he could keep.

"No matter what it takes... I will find him! Find him and bring him home!"

The wind swayed the trees; only the soft rustle of leaves filled the air, and for a moment, time seemed to stop.

"Bring him home?" Shinjuro snorted, unimpressed. "Don't make me laugh. There is no home for a traitor. But if you do manage to find him, do me a favor." His eyes narrowed, contempt seeping out like a poison.

"Cut his head off. I'd rather burry a son than live with a monster."

Senjuro choked back a sob, one trembling hand pressed to his mouth. Shinjuro jabbed a finger at him, voice sharp as a warning. "I told you to stop feeling sorry for yourself! Kyojuro is gone. Get over it!"

Static flooded Tanjiro's ears. His blood boiled.

How...

...can a father be so cruel...?

"Rengoku-san is not gone... you bitter old bastard!" Tanjiro lunged at Shinjuro, fists clenched, shaking with fury.

"Don't do it!" Senjuro screamed, panic cracking his voice. "Father is a former Hashira!"

Tanjiro didn't even have time to process the words before his head slammed against the road. Shinjuro's menacing form loomed over him, a heavy foot pressing into his back. Pain and dust filled his lungs, choking the air out of him.

"I know what you are. Don't think you can fool me, boy." Shinjuro growled through clenched teeth, grinding his heel down harder - Tanjiro's stitches straining under the pressure. "Those earrings... You're a Sun Breathing user, aren't you? You just came here to ridicule our family, didn't you?!"

"Father, please! Let him go!" Senjuro pleaded, tugging at his father's sleeve. "Can't you see he's injured?"

"Shut it!"

The harsh crack of a slap split the air. Senjuro collapsed on his knees, clutching his reddening cheek. For a fraction of a second, Shinjuro's words faltered, his attention flicking to his son.

"Just because it's the strongest Brea-"

But he didn't get to finish, as Tanjiro's head slammed into his jaw with crushing force.

* * *

"I will become a demon." Rengoku sheathed his blade, eye never leaving his opponent. "On one condition."

Akaza blinked, taken aback for a brief moment before a slow, delighted smile bloomed across his face like a bruise.

"I'm listening," he said, crossing his arms, intrigued by the sudden change of heart.

"You will let them live - the slayers, the passengers, all of them."

"As you please." Akaza shrugged easily, smirk never fading. "You have my word."

Rengoku took a deep breath, some of the tension easing from his shoulders. It was a truly hopeless situation, but he couldn't help but feel some irrational sense of gratitude - that even a monster like Akaza had a sliver of honor. He was different - that much was clear from the moment of his unwanted arrival. Over and over again, he asked for Kyojuro's consent to be turned. Countless times, the opportunity presented itself; Akaza could have done it, forced that fate upon him, drowned him in that tainted blood of his.

But he didn't.

He waited - patient, persistent. 

He wanted it to be Rengoku's own choice.

But how could it ever be?

As he stood there, half of his vision stolen, his body already on the verge of collapsing - he didn't feel like he ever had a choice to begin with.

"Let me have a word with the young ones first."

Akaza gave a simple nod, stepping aside.

Rengoku approached the boys slowly, prolonging what was probably the last moment they would ever share. Every bit of strength he had left, he used to appear as steady as possible and yet... meeting Tanjiro's eyes almost made him falter. Wide with fear, confusion, disbelief - it was a wordless don't do it.

But he had to.

There was no turning back now.

"Young Kamado. Boar-headed boy," he spoke calmly, a tone seldom heard from him. "Our roads part here."

"No, no, no, Rengoku-san, please, there must be another w-" 

"There is no other way."

Rengoku smiled softly at Tanjiro - the same way he had many times before. This one didn't reach his eye.

"I don't have much time," he said. "So let's talk. One last time."

The smell of smoke from the train grew stronger; a gentle, cold breeze carried it through the wreckage. The fire cracked faintly, dying away as the flames found nothing left to feed on.

"I have no doubt that someday, you all will become extraordinary Hashira. I believe in you - from the bottom of my heart." 

His hands came to rest on both of their heads.

"Take care of Golden-haired Boy and Kamado girl. Look after the passengers until the Kakushi arrive." 

Rengoku's attention shifted to Tanjiro, his smile turning apologetic.

"Tanjiro, I hate to burden you, but I have a final wish." The boy just nodded, too weak to speak.

"Visit the Flame Estate - my family home. Tell my little brother, Senjuro, to take the path he believes is right... to follow his heart."

"And to my father..."

The words caught in his throat as the image of a man he had never forgotten emerged from his memory.

His father, a few years younger, dignified, with a fiery haori resting on his back.

And the smile he gave his sons - it was blinding, loving, it was-

Gone.

Rengoku lowered his gaze. 

"Please, tell my father that... I'm sorry. I know it's just a wish of a dead man now, but if there was only a way... I would give anything to turn back time, to the moment our family still... felt like one."

He didn't look at Tanjiro again, not trusting the sting he felt in his eye.

Instead, he turned toward Akaza - ever so patient.

"I'm ready." 

He wasn't. 

"Do what you must."

And it all happened so quickly - with a single motion, Akaza forced Rengoku to his knees, clawed fingers gripping his jaw and prying it open.

"You are going to be magnificent," he murmured, blood pouring. "I can feel it in my bones." 

For a moment, it was just a tingling - a small thorn, somewhere at the back of Rengoku's skull. Unpleasant, but bearable. Just hold on until sunrise, he told himself. Keep him down and perish alongside him.

For a fleeting second, he truly believed he could.

How foolish he was to think that.

The first tremor struck his body like a blow to the gut, knocking the breath out of him. There was something crawling under his skin, spreading through his veins and pumping with enough force to break them.

He curled in on himself, gasping, throat tight from panic as the reality set in.

He had to scream - to warn Tanjiro and the others to run, to hide, to get away from him.

They can't. They are injured. The passengers too... They lost so much blood...

And the blood-

It smelled so sweet -  more tempting than anything he had ever known.

Rengoku buried his face in his shaking arms, desperate to block out the scent. But the hollow ache in his gut was unforgiving, deepening, gnawing at his bones. Hunger took hold, calling - pleading - for something, anything to fill the void.

"Aww, don't you want to see your friends?" Akaza crooned, amused by the ordeal. "You were so eager to talk to them just moments ago."

Rengoku shook his head violently.

"You know,"  Akaza chuckled, gripping a handful of his hair and jerking his head up. "I was the one who promised not to eat them. Not you."

Rengoku kept his eyes squeezed tightly, brows furrowing almost painfully.

He would never, ever eat them.

He would never eat anyone.

Never.

So why was he salivating?

"Don't think I've forgotten what it felt like," Akaza went on with his torturous monologue. "That first, overwhelming hunger. You must feel like you are losing your mind, but it's the opposite, really. You are being reborn into something much greater. So stop resisting."

Rengoku clenched his fists, nails drawing blood as he silently begged for the sun to rise. To burn him, to reduce him to ashes - anything, before he lost himself for good.

But the sun wasn't coming, and everything he clung to so desperately was slipping through his fingers. Every face, every memory he held dear - now blurred into something unrecognizable. Nothing was spared by the ever-growing void in his mind, not even his own name.

The last, lonely message echoed back inside him - nothing but the ghost of something he used to be.

He mustn't let it overtake him, he must fight back... for...

For... what?

Rengoku's eyes snapped open - both of them - clear, whole, pupils sharp as razors.

Ahead, a boy was shouting something, but the words were distant, meaningless. There were tears streaming down his face, and the boar-like boy had to restrain him when he tried to stand up.

That scene - it stirred something in Rengoku.

Something he could only recognize as...

Hunger.

A low, guttural sound escaped his throat, silencing the boys instantly.

"What's wrong with you two?" Akaza released Rengoku's head and strolled toward them, steps light, voice almost giddy. When he halted just a step away, his smile cooled into disdain. "Has a single demon's growl become enough to scare a slayer?"

Tanjiro dug his fingers into the grass, eyes fixed on the silhouette behind Akaza.

"Rengoku-san... please... wake up..."

But the person he called for did not answer.

Out of the corner of his eye, Tanjiro saw Inosuke tense - grip on his swords tightening ever so slightly. To Tanjiro's horror, Inosuke's focus wasn't on Akaza.

It was on Rengoku.

"What are you-"

"Monjiro," Inosuke cut in, every hair bristling. "He's bad news. Very, very bad news."

Akaza chuckled.

"Don't tell me you expected anything else." He jerked a thumb behind him. "This - it's a natural course of things. You look devastated, but you should be in awe. His strength is growing tenfold as we speak - already surpassing anything he could achieve as a human."

"And all that power... his to use however he desires. He's not chained by any obligations, nor limits - I set him free."

To use it...

However he desires...

"So, Kyojuro," Akaza said without turning. "What do you want to use that strength for?"

Rengoku's mind supplied him with all sorts of ideas - the possibilities seemingly endless. Yet none of them sparked the faintest hint of joy. 

Maybe... maybe not all of them.

There was one persistent wish, buried deep - etched so far inside him it could never be truly forgotten.

Rengoku took a shaky step forward, then another, still adjusting to his new body. 

As the hollow footsteps carried through the night, sky grew a little lighter in shade, spelling the nearing dawn.

If he had that power...

If he was truly free to choose...

Without a doubt, he would use it for one thing.

To protect the weak.

* * *

"So that's what happened..." 

Senjuro stared down at his knees, hands clutching the fabric of his hakama. Tears streamed freely down his cheeks as a saddened smile appeared on his lips.

"It's such a relief... to know he didn't act upon those instincts," he said quietly. "I... I was so worried. I know he would've never forgiven himself if that had happened..."

Tanjiro glanced at the cup he was holding - tea pleasantly warming up his trembling hands. No matter how many times he recounted that story, it never got easier.

"For a moment, after he opened his eyes..." his voice wavered, guilt slipping in. "I hate to admit it, but I was terrified. I thought it was over."

"If I was there... I think I would have felt the same." Senjuro's voice held only understanding. Tanjiro nodded faintly.

"But when Akaza started approaching us - belittling us - something changed in Rengoku-san. It was like he remembered a part of himself."

It happened in a split of a second.

Tanjiro flinched as something warm splattered across his face. 

Akaza stood before him, his features contorted with shock and pain. His gaze dropped to his plexus - where a white-knuckled fist jutted clean through his body.

"His strength was... unmatchable." Tanjiro shook his head, awe mixing with sorrow as the memory resurfaced vividly. "Rengoku-san fought him mercilessly - scratching, biting, tearing him to shreds. It was carnage-"

He cut himself off when he noticed the fear creeping into Senjuro's eyes and cleared his throat softly. 

"I just wanted to say... that when I saw him fighting - fighting for our sake - I knew he was still there."

Still there... but how deep, exactly?

Because the battle that had unfolded - it truly was a fight between two demons. As much as Tanjiro was relieved that Rengoku stood by their side and not against them, that newfound cruelty relentless determination felt... foreign. Even after Akaza had fled, cursing as he vanished into the dense forest, Rengoku stood there in haunting silence.

And he was looking at them.

But not truly seeing.

"What I said earlier...," Tanjiro met Senjuro's gaze, pushing that thought away. "I meant it. I won't rest until I find him."

Tanjiro believed that if it wasn't for the fast-approaching dawn, Rengoku would have recognized them eventually. But time wasn't on their side, and as the first ray of sun hit the ground, he was gone - off to a destination unknown, even to himself.

"I know father gave up on him... but I didn't."

Senjuro's sniffle carried through the Flame Estate. Fall hadn't really started yet, but a coldness lingered in every room, as one flame wasn't enough to keep it warm all by himself.

"And no matter what he says... I want my brother back, so please..." he bowed deeply, his body trembling.

"Bring him home safely."

* * *

Rengoku had no idea where he was.

For the past few days after leaving Moriyama's house - or rather, nights - he had wandered through mountains and forests with no destination in mind. How could he have one, with that gaping hole where his memories should be? He moved from trail to trail, and when the sun began to rise, he slept in abandoned shrines. During those quiet moments before drifting away, he wondered what his typical day had looked like. As a Demon Slayer, he assumed he always had his hands full with work.

What did he like to do after the missions?

With whom had he spent this time?

Family?

Friends?

Rengoku had already grown used to not knowing the answers- but he was fine with that.

He was sure they would resurface eventually.

Maybe all they needed was a little push.

And in his mind, that little push was returning to what he believed his previous line of work had been.

That was why he couldn't contain the morbid spark of excitement that rushed through him when a scream tore through the night.

"Help...! Anyone, please!"

It was a young woman, sprinting frantically between the trees. Rengoku didn't notice what she needed help with until the demon materialized behind her, claws digging into the hem of her kimono.

Rengoku's hand snapped to the hilt of his sword.

At last.

The night burst with fire as he lunged toward the opponent, severing the demon's arm in one clean swing. It shrieked in pain, clutching the bleeding stump. Three red eyes narrowed at the swordsman, confusion crossing them. Rengoku's muscles tensed almost instinctively, his nose twitching at the metallic scent. The demon recoiled, sensing something in that gesture - and vanished into the darkness.

Kyojuro relaxed his stance, a small sting of disappointment tugging at him. He had imagined a regular fight... a little differently. Weren't demons usually more eager to tear their opponent apart?

"It can't be helped..." he murmured, sheathing his sword with practiced manner. He turned toward the girl. "Miss, are you all right?"

"Y-yes... I'm fine." she said shakily, adjusting her loosened obi. "If it wasn't for you, I would've ended up as a dinner for that-"

She finally lifted her head to look at her savior.

And froze.

Rengoku smiled brightly at her, fangs exposed - relieved that she didn't seem injured.

"I'm glad I could be of help! Do you need me to escort you home?"

"Y-y-y-y-"

"You need to speak up, miss!"

"Y-y-you a-are a d-demon!"

She bolted into the trees, screaming.

Rengoku blinked.

Ah.

So he was.

He knew that, of course - but hearing someone say it out loud...

Rengoku glanced at the severed arm of a demon lying on the ground.

Was he really that similar to them?

His gaze fixed on the hand, studying it closely. The skin was grey, the blood still leaking in a thin, bright stream of crimson. It was probably still warm... 

He touched the corner of his mouth. His fingers came away damp.

...Was he seriously salivating?

He turned his head away sharply, wiping his mouth with the back of his hand in disgust.

But his stomach growled painfully in protest, reminding him of that need he so desperately tried to suppress. Every time he thought he had it under control, it came back - stronger, insistent, and... almost convincing.

No! It was wrong. He couldn't just-

...Right?

He crouched, looking at the severed hand again.

The longer he stared, the more his resolve crumbled as something hollow inside him demanded action. 

Just one bite.

He lifted the arm to his mouth, fangs brushing the skin. He hesitated - but only for a second.

Then his teeth sank in.

His eyes shot wide, pupils dilating at the rush of blood across his tongue.

And then he took another bite.

And another.

And another.

The taste was addicting, intoxicating, warming him up from the inside like a fire as the blood spread down his throat. Something primal curled under his ribcage, satisfied, motivating him to keep going, to have his fill. And he listened, his claws piercing harder into the flesh, every breath coming short and quick. The hunger quieted down as he finished, licking the blood from his shaking fingers. 

That overwhelming relief - it felt wrong.

But he couldn't stop.

It was so...

"Tasty!" he exclaimed, rising to his feet.

He wanted more.