Chapter Text
He grinds the dried flakes of wisteria with the mortar and pestle, keeping an ear on the slow drip, drip, drip of the concentrated poison falling into the beaker beside him. Izuku drops the pestle, adjusts his glasses back on his nose to hover over the beaker boiling on the bunsen burner. The familiar fumes are bittersweet, in both physical sense and emotionally. His classmates know not to bother him as he works, no matter how curious they are. He likes to think himself as a more open person now, but he simply refuses to indulge them on his habit of making wisteria poison. They’ve bugged him relentlessly at the very start of the year but they had eventually given up when all they would receive in reply was a small shake of his head and a sweet, ever present smile.
Yes, Demons do not exist anymore, but old habits die hard. As often as the scent of wisteria brings back unwelcome memories, he still misses it all the same. It’s a guilty comfort of his. Hatsume peers over his shoulder, a hand tinkering with her own project without looking at it.
“Again Midoriya?”
“Of course,” he replies, returning back to grinding the dried flowers.
“Can I experi-“
Izuku cuts her off with a sweet smile, “No.”
Unfazed, she returns to her station. Hatsume knew his answer before she got it. Izuku switches the flame on the bunsen burner to yellow, bringing it to a lower boil. He leaves it to be, walking to the closed off ‘chemistry lab’ that’s more of a glorified (ventilated) box that was only recently constructed on Izuku’s request. It’s more or less his second work station. A small PC sits in the corner, displaying the support lab. It’s there so nothing of his burns or explodes on his table while he’s working in the chemistry lab, but it had been newly revamped by a classmate of his to show the security footage of the entirety of U.A. Unnecessary, considering that it’s mainly Izuku utilising this space, but he admits it’s entertaining at times.
He keeps an eye on Class-1A entering the USJ as he shuffles through his drawers for his supply of wisteria poison. There’s a lot of things in his lab that he would definitely be questioned on if anyone were to snoop around, but luckily his classmates and teacher know to keep their noses out of his business. It’s something he’s very glad of, of course- Izuku is trying to live somewhat of a normal life this time around, a reason why he chose the Support Course instead of the Hero route. This way, he’ll be doing something he’s passionate about while helping others without putting his neck on the chopping board. Maybe it’s selfish of him, wasting his talents and skills. Izuku’s kept up with his health as he would while he was a Hashira, and in no way is he rusty with a blade, he couldn’t forget how to swing a katana even if he wanted to. Even with the years that have passed, his memories have been engraved down to his body and blood. Izuku would be a successful Hero, he could save a lot of lives as one, but he thinks he’s allowed to be a little selfish in his second life. The Gods have given him a second chance, and in no way is he going to waste it. Kanae and Kanao would never forgive him if he were to.
He smiles sadly to himself as he watches the reincarnation of Tomioka isolate himself from his classmates. Todoroki, his name now is, stands far off in the edges of the body of students, his face the same blank slate. Izuku hopes he’ll at least make a few friends this time, he deserves a nice life too. If his old comrade decides to visit him one day, maybe he’ll be that friend he needs. Izuku won’t seek him out, but if their fates intertwine he won’t stop it. He looks nothing like he did as Kocho Shinobu, but fate is a fickle thing, who knows what could unknowingly trigger Tomioka’s memories. Izuku definitely won’t experiment on it. Some things are better left alone.
He takes his eye of the screen for a split second to read a label of a vial of poison when in his peripheral, the small quarter displaying the USJ suddenly darkens. Izuku whips his head to the PC, the wisteria poison gripped tightly in his grasp. There is no sound coming from the footage, but he imagines the shrieks and scraping of metal against metal as he watches large sheets slither over the clear glass of the facility dome. His mouth dries, and the scent of wisteria is suddenly overwhelming.
The Sun. The Sun. There is no longer any Sunlight in the USJ. He jumps to the worst situation possible before he’s even presented any evidence. He’s being paranoid. This is just paranoia, right? His body trembles, his mind racing through millions of theories and possibilities, all of them leading to the same thing. He knows, he knows that they are dead, yet he can’t stop the all consuming fear that wraps and squeezes around his body like a vice. Izuku glues his eyes onto the screen, unblinking, to absorb every detail in hopes to spot something, but then, the screen flickers to black. Izuku isn’t normally one to swear, but in this scenario he thinks it’s fair.
He should tell Powerloader, tell the Heroes and leave it to them. He has no business with a Hero’s job. It isn’t his responsibility.
But it is.
It could be.
If it’s a Demon.
As the Insect Hashira, Kocho Shinobu, this is- could be- his responsibility.
Just in case, just in case, he chants in his head as he strips down his uniform, and replacing it with another. He’s kept it in within hands reach all his life, just in case. His Demon Slayer uniform and his old Nichirin blade had been collecting dust in a hidden compartment in his chemistry lab, waiting for a forsaken day where he would need them. Izuku prayed that his hand would never be forced to do this, alas, he was never God’s favourite.
The gakuran is expertly buttoned on with years worth of muscle memory, and his Nichirin blade is quickly fastened on right after. Last, is his haori, one identical to the one he wore in his past life. His butterfly clip is left behind, his hair is far too short for that now. Within a minute, he’s dressed and ready. Sprinting out the door, he grabs his strongest poisons as he runs, clipping them to his belt.
“Midoriya!” Powerloader calls out to him “What are you wearing? Where are you going?”
Any dread and fear is now wrapped under a sweet, calm smile. There is no worth in panicking, he is a Hashira for Gods sake, buckling under of a maybe threat of a Demon would be disgraceful.
“USJ is currently under attack, alert the teachers,” he evenly informs.
“What?! Midoriya-“
“Sorry Sensei,” he apologises, unapologetically “I’ll explain myself later.”
Ignoring his teacher’s protests, he unsheathes his stinger, thrusting it forward, shattering the window. His classmates cry in alarm, and he leaps through the exit, throwing himself out of a sixth story window. Slowing his decent with the flutter of his haori and arms, he lands softly onto the ground, before pushing off his tip-toed foot, propelling himself into a sprint. Wind rushes through his hair, the world blurring around him as he travels at high speed, one that only the Insect Hashira could achieve. His blade is held at the ready when he arrives at the USJ, and with a single thrust, the doors split open.
A finger twitches, the only crack in his facade as he faces down the first Demon he’s encountered in nearly two decade. He resists the urge to wrinkle his nose at the foul smell of a Demon’s presence, covering up his disgust with a smile. Not a spot of Sunlight in the facility, besides the small crack he forcefully created with his entrance. The light halos around his figure, drawing the attention to his lone form. Like an angel sent from the heavens, he will dispose of these Demons.
“Hello!” he addresses the six students before him, ignoring the misty Demon. “Am I late?”
“Are you a Villain?” a student bluntly asks him, his helmet obscuring whatever expression he’s making.
Izuku laughs lightly, “Fortunately not! I’m a student!”
“Class-B?” someone hopefully wishes.
“Support-course.”
“You must leave then!” helmet-student panics “Please alert the Heroes-“
The Demon cuts in, his short patience run thin, “I’m afraid I cannot allow that.” His (?) mist spreads threateningly, eyes aglow, the yellow piercing the expansive dark.
“I’m afraid, I cannot let you do anything,” his tone tip-toes the dark line of utter hatred and sickening sweet. “Mister,” Izuku brandishes his needle-like blade, poison already coating the metal “tell me, how many sins have you committed?”
His yellow eyes narrow, “Now why should I answer that?”
“Because, it will help me decide how much pain you must suffer before your misdeeds are forgiven. If they are payed accordingly then maybe at the end we can become friends!” He slips into his old routine easily, the rehearsed words automatically spilling at the face of a Demon. It doesn’t matter that he knows the path that it will choose, that all Demons choose, because this is what he knows, what he’s familiar with.
“I’ll pass on your offer,” at least he’s polite “I apologise, I must do my duty and kill you now.” Ah, he takes that back.
“Unfortunate. I must do my duty too then!”
“Blood Demon Art, Warp Gate; Never ending Path.”
‘Insect Breathing, Dance of the Bee Sting-“
He weaves through the endless gates threatening to swallow his body with the grace of a butterfly at blinding speeds, the Demon’s eyes widen when he suddenly is faced with the concealed anger of the Insect Hashira, within the second and the next Izuku dodged the Demon’s attack and closed the distance between them. He rears back his sword-arm, the illusion of butterflies following its path.
‘True Flutter.’
A single thrust, and the Demons metal plating is pierced. Pulling out his blade, he distances the Demon with two swift consecutive kicks. Jumping, he lands on the Demon’s torso, leaning his full weight onto the fresh wound.
“You are a fool-“ the Demon makes effort to heal the injury, ignorant of the spreading poison “a feeble attack like that will not kill me.”
Izuku tilts his head, “Only by decapitation, right? That’s the only way to kill you, besides the Sun. You mustn’t think you’re safe just because you haven’t been beheaded.”
The Demon twitches under his hold, eyes shifting back and forth to find escape. Ah, he can’t let that happen. Izuku thrusts his blade again, pinning the Demon to the floor. “How do you know that?” he grunts out.
Izuku pretends to not hear the question, smiling wider instead in replace of a reply. He retrieves his katana, twisting it along the way for good measure. The mist covering his body hides the effect of his poison, for a fleeting moment he fears that the wisteria concoction won’t work, but then the Demon violently jerks, stilling, then begins to dissolve.
He turns back to the gawking faces of the students, their eyes glued to the spot where the Mist Demon is crumbling to dust. Izuku feels a little bad, witnessing what they thought was an ordinary Villain be stabbed then dissolve by a unknown teen isn’t exactly rainbows and butterflies- well, butterflies, maybe- you get the idea, Demons are traumatising.
But they’re not a priority, his job isn’t finished. He leaps over the students, flipping, and turns his momentum downwards, right to where the second Demon resides. Izuku flies down the staircase, touching down once only to propel himself up again, gaining more speed. A man dressed in black- a Hero- barely dodges a spinning, very sharp looking, spiked mace. The weapon flies back to the Demon, a drop of blood drawn from the Hero’s cheek drips down the mace. The Demon licks it off with a long stripe of his tongue.
“Gross,” he hears the Hero mutter.
He flutters his arms, twisting in the air, and silently lands behind the Demon. The Hero stills, eyes widening. Izuku smiles, putting a finger to his mouth.
“Great weather we have today, don’t you think?” he says into the Demons ear “Maybe we could take a walk together-“ The Demon makes a sound of surprise before he’s automatically swinging an arm, mace in hand, directed at Izuku’s head. He takes to the air again, dodging another swing and retaliates with a barrage of rapid kicks to the chest. “in the warm Sun! It’s rude to interrupt people young man!”
“Who the hell are you?!” The Demon attempts to grab his leg- Izuku springs out the way and distances himself, meeting up with the Hero. Standing between the two, he spins and flairs his sword between his fingers and hands in an almost hypnotic pattern, shamelessly flaunting his skill in front of the two of them.
“Midoriya Izuku,” he charmingly replies “U.A first year, Support-course.”
“You’re that quirkless kid,” the Hero recognises, alarm in his voice.
He hums. “I’ll handle myself,” Izuku reassures.
The Demon smirks, “Quirkless, eh? You suicidal kid? Running headlong into fights will only get ‘ya killed. Fancy tricks mean shit against someone like me.”
“I’ll handle myself,” Izuku repeats. “Hero, you should check on your students.” It’ll be easier if he didn’t have to skirt around the Hero while he fights, keeping away non-slayers far from the Demon will give him more breathing room. Insect Breathing isn’t as destructive like other styles are, but it doesn’t take away the fact that Demons themselves aren’t destructive.
“Midoriya you shouldn’t even be here. Retreat, that’s an order.”
His eye twitches in annoyance. “I advise you to listen to me, Hero. I’ll handle myself.”
“You’re not a Hero student-“
“I am not,” he easily agrees “meaning that you have no jurisdiction over me, Powerloader does.”
“I’m still a teacher here, my authority extends to you.”
“Goodness, you’re a stubborn one aren’t you?” he laughs off his frustration. “If you insist on staying, do me a favour and take care of the nice gentleman over there, the one with too many hands.” Though he smells foul, and his excessive appendages is Demon-like, he is not one. “But please, stay away from my fight.”
“Midoriya you ca-“ Demons are not known for their patience. He’s surprised the Demon has tolerated their babbling until now. The Hero’s hand shoots out, suddenly alarmed, “Watch out!”
Izuku takes to the air, extending his legs to kick away the spinning spikes that were originally aimed at his head. He lands back on the ground, sighing. “What did I say about interrupting people?”
“You dodged,” the Demon states.
He smiles, “I did! Was I not supposed to?”
“Stop playing around Midoriya,” the Hero hisses.
“Ahh, sorry, old habits die hard. I’ll take this seriously now. Hero, take care of that Villain over there, I’ll be finished soon, so just hold him off for a while.” Wisteria poison doesn’t work on ordinary Villains, and he’ll prefer to not cut up a human, despite them having committed crimes, death is too harsh of a punishment. Instead of disposing of the Villain himself before jumping onto the Demon, Izuku will trust the Hero to hold his ground against a C list Villain. “Don’t die!”
Izuku shifts into battle stance, the Demon mimicking him, his hands held out with a weapon readied in each. He allows his opponent to take the first strike, standing still as the Demon closes the distance with rapid speed, becoming a streak of grey in the dark light.
He mutters lowly into the Demons ear, uncaring of the fist a breaths away from impaling his chest, “Dance of the Dragonfly; Compound Eye Hexagon.”
Taking a step back, he delivers a six strike attack, thrusting his stinger in and out the Demons body in rapid succession, each pierce of flesh splatters blood on his dark uniform and injects a dose of poison. Neck, heart, kidney, stomach, then heart and neck again. On the last attack he backs off, the illusion of butterflies fading, and watches the Demon stagger and clutch at his wounds.
“Impressive, but inevitably useless,” the Demon scorns. “You’re like an annoying pest, an insect. Small, fast, bothersome. You think that this will kill me boy? I could swat you away with a twist of my wrist, smother you with one blow, or should I tear you limb by limb, then you won’t be buzzing around any longer.”
“An insect? You’re not very original, young man, if you’re going to insult me at least use something that would actually offend me. But then again, you’re not very bright are you? Kill me with a twist of your wrist, tear me limb from limb? If you could do such things, how come you haven’t done so yet? Sweet boy, lying is a sin, killing is a sin.” Izuku twirls his blade, his expression innocent and kind, “But I’ll forgive you if you answer a few of my questions.”
The Demon takes a step forward, his movements sluggish and slow. “Shut up! Your voice disgusts me, stop your incessant yapping ‘cause all I hear is a pest of a fly buzzing in my ear.”
“Hm, that one was a bit better! Though I’m afraid my voice isn’t the source of the buzz, you’re a bit slow, so I’ll spell it out for you! Wisteria poison is spreading through your system as we speak, killing you at a rapid pace. The dose I injected in you is one of my most potent batches, made for much stronger Demons than you, you have approximately a minute and thirty seconds before you die!”
“Who the fuck are you!? Demons, wisteria, how could a brat like you know anything?!”
“Have you forgotten already? My name is Midoriya Izuku, U.A-“
“Fuck you! I’m going to kill you brat! I’ll just heal my body and get rid your shitty weak-ass poison!” The Demon dashes forward, arms outstretched, his weapons overlooked by his hasty decisions. Izuku sheathes his blade, the fight will be over before the Demon reaches him. Almost humorously, the Demon face plants on the floor, then starts writhe on the ground like a particularly hideous worm. The pathetic creature coughs up blood, black-purple veins bulges out his skin. Izuku stands over the Demon, pulling out a single vial from his pocket, dangling it above the Demons face.
“Thirty seconds, before you die. This is the only antidote,” he holds it closer, teasing the Demon as he tries to weakly reach out to the vial “I’ll give it to you if you answer one question.”
The Demon garbles out an unintelligible sound, but it sounds agreeable enough. “Tell me who your master is.”
“Se- se..nsei. Se..nsei is.”
Izuku breaths out a relived sigh, “Last question: have you heard of the name Kibutsuji Muzan?” He asks to confirm.
The Demon shakes his head, eyes rolling around crazily, blood spilling from them. Izuku keeps his promise, unfurling the Demons’s fingers, he places the vial into its hand. He squeezes the Demons hand, making sure the antidote doesn’t fall out. “There you go! Make sure to take the antidote soon! You have about 10 seconds!”
Maybe he’s being cruel, tantalising the cure to his life by the nose, knowing that the Demon is unable to make the simple movement of pouring the antidote into his mouth. But he’s not Tanjiro, he doesn’t have any sympathy for Demons like he does. Nezuko was a one in a million chance, her kind is rarer than rare, the Demon by his feet is definitely, definitely not one of them. The body begins to dissolve.
“Oh no!” he cries out in false alarm “Sweet boy, you’re dying! Hurry, hurry! Take the antidote!”
If the Demon could speak, he imagines that he would be spitting curses at his face, but all he manages is a furious glare before the Demon completely dissolves. The still intact antidote clinks onto the floor with no one holding it any longer. Izuku retrieves it, tucking it back into his pocket. Turning, he leaps off his foot, heading towards the Hero’s direction to check up on him. He hopes he’s still alive.
Fortunately, when he arrives the Hero is alive, albeit a bit roughed up and ragged. Unsheathing his blade, he knocks away the hand reaching for the Hero’s elbow, creating a shallow cut across his palm.
“You. Where’s Kurogiri?” the Villain snarls “What did you do to him?”
“Kurogiri? I don’t know a Kurogiri, but if you’re talking about one of your companions- they’re both dead!”
The Hero’s eyes bulge out of his sockets, “You killed them?!”
“Oh my bad, was I not supposed to?”
“Midoriya we’ll talk about this later,” the Hero promises, warning edging his tone.
“There’s no way a brat like you killed those two.” The Villain raises his wounded palm before twinging and switches hands to scratch harshly at his own neck. Wisteria poison is not deadly to humans, but that does not mean it has no effect on them, it is still poison after all. To those unused to its effects it can cause severe rashes, nausea, dizziness and shortness of breath.
“Sorry about that, I forget that not everyone is used to my poison like I am! It’s uncomfortable isn’t it?” Izuku bows his head politely, placing a hand over his hilt, “Would you like me to stop the pain then Mister?”
The Villain ceases his scratching. “You’ll really kill me huh? Not very heroic.”
“Well, good thing I’m not a Hero!”
In one swift movement he wipes any remnants of wisteria poison on the fabric of his haori, dashing forward in the next second. Again, he knocks away an offending hand as he leaps right above the Villains head and sends a precise kick to the pressure point on his neck, knocking the man out in one blow. He touches back down gracefully, hovering over the Villains unconscious body.
“Hero, are you injured?” Izuku didn’t being his medical supplies with him but he does have a spare roll of bandages in his pocket.
“Are you?” he shoots back, ignoring his own question.
“Not a scratch. Are you injured?” he repeats, more sternly this time.
Something must show in his voice or face because the Hero’s reply is near instant. “Surface injuries. The Villain had some type of disintegration quirk, he got me a couple of times.
Izuku beckons a hand, unrolling the roll of bandages as the Hero approaches. “Roll up your sleeves, or take off your shirt if that’s more comfortable, carefully,” he adds.
“I can bandage myself.”
“You can, but it’s advisable not to. Sit.” He does. Taking a look at the sluggishly bleeding wounds, he inspects for any abnormalities before starts working. The skin is cracked and grey around the edges, the deepest part of the wound exposes his muscle but it doesn’t go and further than that. “I’ll stop the bleeding, but I don’t have anything to prevent infection or the pain,” he wraps the bandages around the Hero’s bicep as he speaks “Recovery girl can heal you later, but if you prefer to reserve your energy you can come to the support lab and I’ll be able to treat you there.”
“You’re good at this,” the Hero observes.
He hums, cutting off the excess bandages with his blade, “I’ve had my fair share of experience.”
“That’s an interesting..sword?” he half-asks, half-states.
“It’s a sword,” he confirms “a katana to be more specific.”
“Where did you get it from?”
“Questions later, Hero.”
“Just call me Aizawa-sensei Midoriya,” Aizawa- not sensei, because he’s technically not his teacher- nods in thanks once he’s done with wrapping his wounds. “Would you actually be able to treat my injuries?”
Did he not just say to ask questions later? But he guesses this question is harmless enough. “I would. I don’t have any pre made tonics, but I’ll make one if you need.”
“Thanks, but I’ll pass on it.”
Izuku nods, not really too shocked by the rejection. It makes sense Aizawa doesn’t trust Izuku to heal him, he did recently admit murdering two ‘Villains’, that he doesn’t know were actually Demons. Izuku sighs internally, he’s gotten himself in a terrible mess because he couldn’t keep himself from butting into others business.
Live a good life, he said, Live a long life. Curse the Gods for showing the inability to leave him the fuck alone.
“Midoriya?” Aizawa calls “Are you alright?”
He immediately smothers his anger, smoothing out his face and replacing his scowl with a smile. “I’m fine Aizawa-san, just thinking.”
The Hero frowns at his choice on honourifics, but doesn’t comment on it. “About what?”
He hums dismissively, “Nothing that concerns you. The heroes should be arriving soon by the way, I told Powerloader to alert the teachers before I left.” They’re awfully slow, Izuku internally thinks. He would’ve thought they would’ve been in more of a rush if their students were in danger, but he guesses they can’t be blamed- Izuku hadn’t really elaborated when he warned Powerloader, so it must’ve taken a while to check if the USJ was actually under attack and then gather the heroes.
“How did you get here so quickly, or even know USJ was under attack?”
“There’s a screen in the lab displaying the security footage of U.A’s campus, when the footage suddenly cut out, I assumed something was wrong and ran here.”
“The USJ is ten minutes away from the main campus, and that’s by bus.”
Izuku smiles, “I’m much faster that a bus, Aizawa-san.”
“Thats impressive kid.” Kid. Funny, he’s technically older than the man. “You fight well, though I don’t approve of murder, and the fact that you ignored my orders, I’m still grateful.” Aizawa inclines his head “You fought for both my students and I, thank you.”
For the first time today, his smile is genuine. “It’s okay Aizawa-san, I just did what’s right. The protecting part of course,” he adds “not the killing.”
“Glad to hear that kid, you still have a lot of explaining to do though.”
“I know, but let’s save that for later. The heroes are here.”
On cue, the doors burst open, properly this time, unlike Izuku they used some type of mechanism to reprogram the lock on the door instead of stabbing their way in. All-Might stands proudly at the front with the principal on his shoulder, the rest of the teachers hang a step back, quirks and weapons at the ready. They look around confusedly when they see no Villains in the immediate vicinity, slowly lowering their weapons.
“Aizawa-san, I think it be best if you report to them. I’ll stay here with Mister hands just in case he wakes up. Oh, and tell them to gather the students, they’re spread across the facility.”
Aizawa sighs lowly through his nose, “Midoriya, you can’t keep ordering me around, I’m your teacher.”
“I mean no disrespect Aizawa-san, and you’re not my teacher,” he reminds.
“Maybe I will be one day, you’d make a good hero.”
“Maybe. But I don’t want to be a hero.” He’s been in enough fights to last five lifetimes. Dying young again isn’t a goal of his. He doesn’t want to be a hero, but if Demons are back he might not have a say in whether he fights or not. “Though I may change my mind.”
“You’re very adept at combat for someone who doesn’t want to be a hero.”
“I like to keep myself fit, and I guess combat just comes naturally to me.”
“Midoriya Izuku!” Powerloader calls from the staircase, running down as he yells. “You have some explaining to do young man!”
He lets his teacher catch up to him before he speaks. “Hello Sensei! Sorry for running off like that!”
“Midoriya.” Powerloader scans his body, checking for any injuries. “Is that your blood, are you hurt?”
“It’s not mine,” he reassures “Aizawa-sun over here is hurt though!”
His teacher points an accusatory finger at him. “Don’t try to change the topic Midoriya. Are you alright Aizawa?” he asks the Hero anyway.
“I’m fine, Midoriya bandaged me.”
“You’re full of surprises aren’t you kid?” Powerloader sighs. “First you’re breaking my windows then you’re jumping out of them and running to fight a bunch of Villains. And here I thought Hatsume was the wild one, you were supposed to be my star student Midoriya!” His teacher spots the purple, wisteria coloured stains on his haori, and sighs again. “You used your poison?”
“You use poison?” Aizawa interjects “Where did you-“ he stops himself. “Right, support-course. You made it yourself.”
“So this is why you kept on making the same poison over and ever again. To fight Villains.”
“Well, not exactly Sensei!”
If he weren’t wearing a helmet, he’d see his teachers eyebrows shoot up. “What do you mean?” he asks cautiously.
He leans in, holding a hand to his mouth like he’s telling a secret. “Ne, ne, Sensei, have you ever heard of Demons?”