Chapter Text
Shinobu’s path had been set as soon as she lost Kanae. If she could help people, if she could save people, so they wouldn’t endure what her sister had to, so they wouldn’t grieve for the rest of their lives like she did, it still wouldn’t be enough for her. Not enough, but it would be better than nothing, and she was capable.
Defeating every demon until they no longer walk the earth—that may be close to enough. Impossible for her alone.
Wisteria was her sister’s favorite flower. Toxic, but Shinobu never knew the extent until the pieces started coming together. Wisteria, beautiful, but so deadly. Toxic even in small doses, if ingested. She’s not sure Kanae knew just how valuable that flower would become, or if she’d only admired its beauty from the eyes of someone who only made it to seventeen.
She hasn’t seen the other Hashira in weeks, confined to a lab more brilliant than she could ever pull together in the Butterfly Mansion, forced to ally with two demons she’s more comfortable with seeing as enemies.
But still, they’re knowledgeable, and can work long hours without the threat of sleep creeping over them, whereas Shinobu prioritizes work over rest, only to see purple when she shuts her eyes.
“You spend so many silent days here, I’m starting to believe you don’t speak,” Tamayo says with a slight smile. Kind, welcoming, everything a demon should not be. “Have you made any progress?”
Not enough, but it’s been that way for years. Poison him. Kanae hadn’t even had to say it for Shinobu to know it would be her only chance. Her hands are so small, and she hadn’t grown much taller than she was when she lost her sister. Kanae had been delicate, but nothing like Shinobu, who can’t train enough strength into herself to slash a demon’s head off in a single stroke, not like the other Hashira.
Poison him. Even in death, Kanae had been so kind as to not tell her sister the undeniable truth that someday, Shinobu may just lose to that same demon, if they cross paths. Everything Kanae may have wished against in her final moments is everything Shinobu wants in the end. Find him, kill him, even if poison is her only option.
She is supposed to help work on a drug to defeat Kibutsuji, and she does. Her lack of rest comes from her own research, and the extra hours she dedicates to Upper Rank Two’s downfall.
“Don’t know,” Shinobu says, keeping her eyes on her work, avoiding Tamayo’s gentle gaze. She is, to say the least, difficult to maintain a cold distance with when Tamayo doesn’t act like a demon should. Shinobu feels like she is betraying herself every time she thinks she might trust her, just because the Master does. “We can get Yushiro to test it.”
“So much evil in such a small frame,” Yushiro says, baring his teeth.
“That is simply not true,” Tamayo says. “But she has a sense of humor, I see.”
Their ideas of humor must be entirely different since she was serious, although using Yushiro to test her poison only aligns with her own ideals, and goes against the Master’s plan. She can only hope that it’s well-thought out and not in vain.
“What do you know about wisteria?” Shinobu asks her.
“Very talkative tonight,” Tamayo smiles. If it were coming from anyone else, Shinobu might sense the sarcasm that lines each word, but coming from Tamayo, she’s sincere. It’s conflicting. Unnatural. A demon shouldn’t be anything but selfish, yet here she is offering help to humans to kill her own kind. Shinobu should be grateful, and she is, but not without hesitation. “I know a great deal about it, as I’m sure you do.”
“How much wisteria would it take to be fatal?” Shinobu asks, committing to breaking her streak of silence. Too straightforward, too blunt, but Shinobu isn’t someone to dance around truths. “How much would it take to kill you?”
“To kill me? I’m not quite sure,” Tamayo says. “Is that something you’re interested in finding out for yourself?”
Yes.
No.
Yes, because you’re a demon.
“Not you,” Shinobu says.
“Then Yushiro?”
Yes.
“Demons. Strong ones. Specifically an Upper Rank,” Shinobu says. A demon much stronger than Tamayo and Yushiro’s combined forces, one Shinobu stands no chance against.
Shinobu glances away from her work, just to see what keeps Tamayo from answering. She looks at Shinobu with sympathetic eyes, soft and understanding. Shinobu shouldn’t like the way her gaze feels on her, like this demon looks at her and sees her beyond the shell of what she once was. Like Shinobu can’t fool her, even if she tries. “Much more than a human, since most varieties are toxic when ingested. But I’m sure you know that already, don’t you?”
Never has Shinobu thought her facade could be seen through so easily when she hardly gives herself away. But Tamayo is right. The burning sensation in her mouth, the sharp pains in her stomach, the vomiting, retching her insides until there was nothing left when she’d ingested too much.
But humans are painstakingly weak compared to demons, and what has made Shinobu so sick she’s been brought to her knees would do nothing to an Upper Rank.
“You’re not frail, but you’re weakened,” Tamayo continues. “The other Hashira may not know this, but I can see you’ve been testing your limits for how much wisteria you can consume without serious harm.”
“It’s nothing to worry them with,” Shinobu insists.
“It is unnecessary.”
“I can’t cut a demon’s head off on my own,” Shinobu says. Tamayo must know that too, just by looking at her. She knows exactly why Shinobu has devoted so much of her life to medicine, to healing, when the destruction she seeks is not something she can execute on her own.
“So you inject them with poison using the tip of your blade.”
“You’ve seen it?”
“No, just an assumption I made after observing you.”
Shinobu’s face burns with shame, and she fights the urge to slam her work down in frustration, knowing a demon has figured her out, even without combat. If Tamayo can see through her, who is to say Upper Rank Two won’t as well?
She needs to work harder. She needs to do more. She needs to make sure her plan succeeds or it will have all been for nothing.
“Demons require much more than a human. Our metabolic rates are different—faster, which could be used to your advantage, since you won’t have to wait hours for it to work through our system,” Tamayo says in earnest. She explains as if it doesn’t go against her own nature as a demon, like plotting to kill her own kind is nothing but a typical occurrence. “But because it’ll work through our bodies much quicker, we’ll neutralize it before it’s able to do any harm if it’s not enough.
“How much is enough?” Shinobu asks, feeling herself grow desperate.
She has no choice but for her plan to work. There is no other option but to avenge her sister and defeat Upper Rank Two, all while aiding the Corps in victory. There is no other option. They must win.
Tamayo sighs. “It depends on the demon. Upper Rank Six would require much less than Four, for example. And with both of them dead, if it were decided to fill those vacancies with other demons, much less since they wouldn’t have the acquired strength of a demon who’s been an Upper Rank for a century.”
“Two,” Shinobu confesses. “It’s Upper Rank Two.”
To avenge her sister. To kill the demon who took Kanae from her, who left her and Kanao without the only person they had left.
Shinobu has once told Kanao how to defeat that demon, should she ever come across him before Shinobu can, and even then, her words were uncertain. Tamayo’s expression tells her she’s right, and that she has no idea what she’s getting herself into, even with her experience as a Hashira.
Kocho Shinobu, Insect Hashira, physically weak and naive and completely in over her head.
“As much as possible,” Tamayo tells her gently. Her tone almost feels like there is no hope in Shinobu’s plan. “And then more.”
Before she can think otherwise, a small fist plunges into the table beneath her. Shinobu has no room to fail, but she cannot keep poisoning herself with the hope that she won’t have to use her last resort. She cannot move forward without that plan B while not knowing whether the poison in her sword will work against the demon or not. In every possible scenario, Shinobu loses, just like her sister had tried to tell her. In every choice Shinobu has made so far, she hasn’t chosen survival, just a delayed death.
And apparently, she’s needed another demon to tell her that.
“I’ll help you,” Tamayo tells her, reaching for her hand, treading lightly. Her skin is cold, unnaturally so against Shinobu’s warmth. She truly feels like an ally, even when she shouldn’t. “My priority is the drug we’ll use to stop Muzan, but tell me what I must do to help you defeat Upper Rank Two, and I’ll do it.”
Demons, by nature, are deceiving. They’re cowards, and manipulative, and they never quite mean what they say unless they’re taunting their prey. But when Shinobu looks at Tamayo, her eyes are honest, and she squeezes her hand like someone who’s been on her side for longer than she has. Like someone who wants her to win, someone she can lean on. A demon she can trust. As wrong as that is.
“I’d have to expose you to the poison I’ve made,” Shinobu tells her. I’d have to risk harming you. I’d have to put everyone at risk, because Shinobu knows they only win with Tamayo at their side.
Tamayo nods. Recklessness transcends humanity, and what comes when you’ve given it up. “Then let’s begin.”
••••
It only takes five vials for Yushiro to decide he’s had enough. It takes Tamayo twice that to start sweating profusely and the already-lacking color to drain from her face, replaced by purple splotches that resemble bruises and a weary look in her eyes.
“I assume that’s enough for the night?” Shinobu asks, although she wishes they could keep going, for reasons that have absolutely nothing to do with sadism.
“It might… have to be,” Tamayo forces out, exasperated.
“We can rinse your mouth out,” Shinobu suggests. “That’s what I do when I’ve had too much.”
“I’ll neutralize it soon,” Tamayo says.
Within a few minutes, she does, and it’s as if Shinobu hadn’t done a damn thing. Her work is lackluster, and she is no closer to finding a solution than she was three years ago. She is back to square one every single time. It is the life of a scientist, hypothesizing and experimenting, then going back to the drawing board and doing it over again. Scientist wasn’t exactly Shinobu’s occupation of choice, although neither was demon slayer. Neither was doctor. She hadn’t grown up enough to truly choose, just take the roles that were given to her, and accept what comes with them.
Shinobu tries to keep her mind off the failed attempts, if only to distract herself from the disappointment that has replaced her success, and the disappointment in herself for feeling disappointed at all. Had she succeeded, Tamayo would be dead, and she can’t have that. Truthfully, she doesn’t even want it. Tamayo’s death at her hands doesn’t guarantee Upper Rank Two’s downfall, however, her survival guarantees his.
She runs the velvety pods between her fingers. The deadliest part of the wisteria plant, but not deadly enough. Not yet. Surely there should be another way to concentrate her poison, to make it so lethal in doses small enough to be discreet. But it’ll remain a gamble until the end, with no way of testing its true efficacy, even if Tamayo continues to offer.
“You remind me of myself sometimes,” Tamayo tells her, the hint of color returning to her face. The natural tint of her lips comes back, previously pale with a sickly hue due to the poison. She looks healthy—as healthy as a demon could be.
Something like relief flows through Shinobu, just seeing she’s okay. It shouldn’t. All this should tell her is that an Upper Rank would metabolize this much faster than Tamayo did, and that this is nothing but a failure.
“You don’t take loss well,” Tamayo continues. “You fight it.”
“Excuse me?”
“With your work. You make a goal and you work to reach it, but when you don’t, it is enough for you to question your self-worth. You shouldn’t do that, if you know what’s good for you.”
“I know what’s good for me,” Shinobu says, tightening her lips.
“And is that poisoning yourself rather than asking for help?” Tamayo asks. “You have good allies, yet I don’t see you utilizing them.”
“I’m utilizing you.”
“Yes, but it’s fair to assume I’m different. There is less risk when it comes to me, since most times I will just heal. Your human allies, on the other hand, are just that. They are human. One mistake can be the end, and I think you know that well enough, so you won’t ask them.”
She’s right. Shinobu hates just how right she is. She looks up and half-expects the smug I told you so look on Tamayo’s face that she might see on anybody else, but is met with eyes that look like her own instead. The same violet hue, the same eyes that have seen pain and endured it all the same, the same ones that hold it together for the sake of everybody else.
“You remind me of myself sometimes because you don’t quit, and you don’t know when to give up,” Tamayo tells her, reaching her hand to touch Shinobu’s, just slightly. Gently, with just a swipe of her fingertips. “You persist, even when it’s damaging. Even when you’ve passed the point of no return. I’ve lived many lives in my time as a demon, and made choices I’m not proud of, ones I can’t take back. The cost of immortality is living with those choices. I see you doing the same, except there is no infinity to fall back on for you, as a human.”
“It’s none of your concern,” Shinobu says, shaking her head, ridding herself of every thought that may tell her that Tamayo is right, and in her efforts, she is throwing her life away. And that Shinobu does not wish for her sister’s fate, but must settle for it if it brings victory. That in becoming a Hashira, that was always a risk.
“I don’t want you to die,” Tamayo says, smiling gently. How unnatural it is for a demon to not wish death upon a demon slayer. To not inflict it, to wish for a fulfilling life instead. “My body has recovered from the poison, so let’s continue.”
“There’s no use,” Shinobu says. “It will be the same thing, and we won’t get any closer to perfecting it without killing you. The effort is for nothing.”
“The effort is not for nothing if it means you get to live past the years you expect for yourself. So let’s continue,” Tamayo says. “Put your trust in me. I’ll help you.”
Shinobu wonders if it goes against her sister’s will to say she already has. If it goes against the ideals she accepted once she lost her. If it goes against who she is as a Hashira.
She wonders if there’s forgiveness in the end for someone who can trust a demon, not out of desperation or obligation, but because she wants to. Because although she knows she should be content with calling this demon an enemy, for accepting their natural order as it is, Tamayo is not an enemy at all.
An enemy doesn’t put their own life on the line just for a chance that Shinobu will live, for a chance that she’ll win. Even if that chance is slim.
It feels like accepting defeat. Defeat by someone who should not be beautiful, and should not look at Shinobu with all the warmth that demons lack. She starts her preparations for one more vial, hoping that in the end, she’s doing the right thing. One day, soon, she’ll find out.