Chapter Text
Today was the worst day in the history of bad days. It seemed fitting that this was the one way Izuku beat Kacchan. Not only had school been…well, school, but the teacher just had to ruin Kacchan’s good mood by reminding him of Izuku’s heroic dream. In front of the whole class. Izuku really shouldn’t have expected anything different.
Kacchan, of course, took Izuku’s desire to be a hero as a personal affront and burned his notebook before tossing it in the fountain. Then he’d said…
Izuku shook his head violently, tears pricking the corners of his downcast eyes. (Downcast because every time he looked up his eyes wandered to rooftops.) He wasn’t sure if that was the worst part of today, or if it was what came after. Being suffocated and drowned in an underpass by a villain, then rescued by All Might, then crushed by that same hero when Izuku dared to ask the only question that ever mattered since he was four.
Izuku should have known better, really. He didn’t even believe in himself anymore. Why should someone else?
Izuku let his shoulders sag in resignation as he kept putting one foot in front of the other. He had no idea where to go from here, but he knew where his feet would take him if he stopped moving. (He’d stood on that rooftop a long time after All Might left.) His dream was broken, but something in him refused to give up on everything else too.
A metallic thud startled Izuku from his dazed trek. He jerked his head up, whipping it around to look for the source of the sound, tensed to run. Had his bullies really laid in wait for him this long after school let out? Wasn’t Kacchan’s “talk” earlier enough? How did they even learn he took this route? He’d picked it specifically for the lack of people.
When he finally located the source of the noise, he froze. He’d stopped at the mouth of an alley, and at the far end, the Sludge Villain was in the middle of strangling/drowning a middle-aged woman. Horror crawled up Izuku’s spine and squeezed his lungs in sympathy. All Might caught the villain; so how…?
Izuku paled as he realized this was his fault. All Might must have dropped the bottles while making sure Izuku didn’t fall on their cross-city jump.
Izuku’s eyes refused to leave the woman as she struggled to no avail. Finally, the pair shifted enough for Izuku to get a look at her face. Her eyes were wide and filled with fear, panic, and pain. Izuku had seen eyes like those too many times on the playground when he was little. He’d always stepped in then, putting himself between Kacchan and whoever he was hurting.
Izuku found his feet moving before he could even begin to think. There wasn’t much to think about anyway. Even if he couldn’t be a hero, he was going to continue stepping between bullies and their victims. That was something he’d always been able to do. But to step between these two, he first had to create space between them.
Izuku threw his backpack at the Sludge Villain with all the strength he could muster, yelling to draw the villain’s attention. The amorphous man turned to get an eyeful of textbooks and pencils as they flew from where Izuku had forgotten to zip the bag shut.
“You again? Ow!”
While the Sludge villain reeled and squinted—how did that even work when he didn’t have eyelids?—Izuku clawed at the sludge covering the woman’s face, trying to free her airway. He never thought victory could sound like a wet cough, but that had to be the best sound he’d ever heard.
The moment of success was short-lived, however. The sludge condensed around Izuku’s wrists, suddenly clinging too tightly for Izuku to pull away. It squeezed painfully as the villain leveled him with a slightly bloodshot glare. “You little punk! I’ll deal with you in a minute.”
The slime wrapped around his wrists lifted him in the air before flinging him. Izuku hit the opposite wall of the alley. The air rushed from his lungs, and his head spun and throbbed from where it contacted brick. He slid down the wall to land on a pile of garbage bags and tried to blink the spots from his vision.
A muffled scream sent a shot of adrenalin through him, and the world snapped back into clarity. Mostly. The Sludge villain was smothering the lady again. Izuku attempted to climb to his feet but fell back when the garbage bags shifted under him. “Stop…” he said, voice sounding small in his own ears.
“Stop hurting him, Kacchan!”
The funny thing with Izuku stepping between a victim and their bully? He’d never been able to fight off a bully, but he could make himself their target long enough for the other kid to get away.
“Stop!” Izuku said with more force. When the villain still didn’t respond, Izuku steeled himself and yelled as loud as he could, “Stop! Take me instead!”
The Sludge Villain and the woman both blinked in surprise and stared at him.
“Don’t…don’t hurt her. You can have me instead. I-I won’t fight you. Just let her go. You don’t need to hurt anyone.” Izuku shrank in on himself as the ramifications of what he’d offered sank in. He didn’t want to die, not really. But he wanted someone else to die for his mistakes even less. And well, wasn’t this what a hero would do? (Not that he could ever be one.)
The Sludge villain scrutinized Izuku, and Izuku did his best to meet his gaze head on, despite the tears steadily rolling down his cheeks. He wanted the villain to know he’d meant it. The villain seemed to reach the same conclusion, because his creepy smile spread even wider. He chuckled. “Oh, this is going to be good. I haven’t had a willing meatsuit in over a decade.” A slimy tendril plucked Izuku from the garbage pile by his waist and brought him to hover in front of the villain’s face. “You’d better remember your word, brat. You struggle, and I might just decide to off a civilian or two for funsies.”
Izuku swallowed before saying barely above a whisper, “I understand.”
The Sludge villain’s eyes narrowed as he smirked. “Good. Now, to take care of the witness.”
Izuku didn’t have time to protest before the woman was flung against the wall, much the same as he’d been moments before. Sludge covered Izuku’s mouth to silence his scream. More wrapped around his arms and legs, restricting his movement.
“Don’t be so dramatic. I just knocked her out. See, she’s still breathing.”
She was, in fact, still breathing, which made Izuku relax marginally. The villain rifling through his pockets until he found Izuku’s phone and tossing it and his backpack into the trash was slightly less reassuring. With the matters of witnesses and potential tracking devices settled, the Sludge villain carried Izuku deeper into the maze of alleyways with surprising speed.
“Now, here’s how this is gonna go, kid,” the villain said, drawing Izuku’s attention again. “I’m going to keep your airway open as long as possible, and you’re going to keep taking deep breaths through your nose the whole time. Focus on that and not struggling, and this’ll be over nice and quick.”
Izuku tilted his head in confusion, what was the point of keeping his airway open if the guy was going to kill him anyway? With his mouth covered, he couldn’t really ask. So, he just nodded. At least the villain didn’t seem intent on gloating or drawing out his suffering.
“Open wide.”
Izuku reluctantly complied, gagging on the taste of sewage that rolled over his tongue for the second time in an hour. It was somehow worse this time. The sludge slithered down his throat, and Izuku’s body tried to expel the nauseating stuff. A few unsuccessful heaves left Izuku tired and shaking as he dragged air into his lungs through his nose.
The Sludge villain laughed and said something about things not being so bad once you got past the gag reflex, but Izuku tuned him out and tried very hard to tune out the feeling of the steadily increasing volume of sludge forcing its way into him. His throat and stomach had been on fire at first, but they were settling into an odd, burning numbness now. That sensation was spreading too.
Nope, Izuku was not thinking about that. He wasn’t starting to hyperventilate either. The villain wanted him to take deep breaths, and Izuku didn’t want to test how much it took to make the guy angry. What was that breathing exercise he’d seen online again?
Izuku clamped his teary eyes shut and counted seconds and breaths, quickly losing track of time. It couldn’t have been too long. The villain had said it only took 45 seconds the first time. How could so little time feel like forever? As soon as he’d formed the thought, the villain said something, but Izuku couldn’t make out the words. It sounded like he was underwater, and everything was miles away. It felt like he was underwater too, with pressure bearing down on him from all sides. Dizziness and darkness played at the edges of his mind. He finally slipped under when something cut off his air.
-|-|-
If you're hearing audio of this or seeing it reposted somewhere other than Archive of Our Own, I did not consent to it, and this person is stealing. Please report them. You can find the original work on ao3 under the title Residual Hope.
-|-|-
Awareness crept back to him like a brush fire, in painful starts and jumps. His everything hurt. He didn’t know that was possible, and he wished he still didn’t. Quirks, even breathing and his heartbeat hurt. And movement. Why was he moving? He whined, or at least, tried to.
“Oh, there you are, Midoriya. Took you awhile. I was starting to wonder if I’d lost my touch.”
“What? What’s happening?” He slurred. Oh, right. He’d hit his head earlier, hadn’t he? He didn’t think to wonder how whoever this was knew his name.
“Eh, don’t worry. The pain’s just your body trying to kill me, and my body trying to kill you. Immune response is a bitch. Things’ll settle out in another few hours.”
“Hours? I feel awful.”
“If you’re just going to whine, take a nap,” the voice said, sounding miffed. “Not like you’ll miss much.”
Something shifted, and Izuku felt pressure on…his mind? It was weird whatever it was, and he pushed back against it.
“Ah ah ah, no struggling. Or did you already forget our deal, kid?”
Izuku froze, recalling struggling was bad but not what specific context this person was talking about. Fighting back against the kids at school never went well; he got hurt more when he fought back. Several examples from the past semester played out in his mind. It made sense that it was the same here. After a few moments’ deliberation, he stopped resisting. The pressure returned, almost hesitantly, and Izuku slipped back into the dark.
The next time he woke up, thinking was easier, and he didn’t feel so much like he’d been on the receiving end of one of Kacchan’s beatdowns. Everything still ached, and he felt weak and kinda sick, but he was still standing. Wait…Izuku realized that his eyes were open. (How had he forgotten that? When did that happen?) Why was he standing…in a train station? And why was it dark?
“Welcome back. Again.”
This time memories rushed back to go with the voice. “Sludge?”
Izuku got the distinct impression of a cringe. “Yeah, never call me that again. Why does everyone assume it’s sludge? It’s slime. There’s a difference,” the villain groused.
Izuku made a mental note of that for later, because apparently, there was a later now? Izuku ran through a series of small, attempted movements, but his body didn’t respond in the slightest, instead stepping forward after an overhead announcement for an arriving train. He was definitely not in control of his body, right now, and he didn’t recognize the name of the station they were at. Okay, he needed to focus on something else. “Um, not that I’m complaining, but why aren’t I dead?” Okay, this topic wasn’t much better, but he was curious.
Izuku heard a sigh and jolted to attention when he realized his body hadn’t sighed with it. Did that mean they were communicating mind to mind? Part of him had so many questions. Another part of him felt queasy at the thought of part of the Slime(?) Villain’s sewage-flavored body being inside his skull and somehow attached to his brain.
“You’re alive, because you kept your side of the deal. Most meatsuits tend to waste their oxygen by pointlessly struggling. Also, it’s really hard to keep all of my body out of a person’s lungs when they won’t stop moving and trying to scream during the process,” the villain said dismissively. “After a while you kinda give up trying.”
Izuku shuddered at the villain’s callousness, surprised when his body responded to that of all things. So, the villain’s control wasn’t absolute after all. Maybe he could—
“I’m gonna stop ya right there, Midoriya. You really want to start struggling with all these helpless civilians around?” The villain trailed Izuku’s eyes over the crowded train car, lingering on the particularly vulnerable ones: a little girl and her grandma, a woman with a newborn, a gentleman with his arm in a cast.
Any plans of fighting back died instantly. Izuku’d already gotten that one woman hurt by distracting All Might and letting the Slime Villain escape earlier. He didn’t want anyone else to get hurt. “So, w-what now? And how do you know my name?”
“You had your school id and train pass in your wallet. As for what you’re going to do? You’re going to sit back and relax. I’m getting as far away from Musutafu as possible in 24 hours.”
“Why 24 hours?” Izuku asked, almost dreading the answer.
The Slime Villain rolled Izuku’s eyes. “You always this chatty? ‘Cause 24 is as long as I’ve ever held a willing possession. Granted that was when I was about your age. Maybe my time limit’s longer now, but I don’t want to chance it.”
Izuku didn’t want to contemplate what might happen at the end of that time. So, he distracted himself like he always did: quirk analysis. He reviewed Mt. Lady’s debut from that morning and Kamui Woods. He thought about All Might’s quirk—which seemed stranger and stranger each time he thought about it.
Then he thought about the Slime Villain’s quirk. It was so weird that he’d figured out how to possess people when it looked like he had a simple mutation quirk. Maybe his physical appearance wasn’t his quirk after all? If it was a vestigial mutation and the possession itself was his quirk, that made slightly more sense. Quirks like that tended to come with some degree of instinctive knowledge on how to properly use them. Taking over someone’s entire body without hurting them (and sure Izuku ached a bit, but he wasn’t hurt, per se) seemed like it would be pretty complicated to do, not something a person was likely to figure out on their own.
Of course, Izuku could be discounting how intelligent the villain was. Maybe he was in med school before he went villain and just knew that much about anatomy and physiology. Then again, the guy did say he’d pulled off willing possessions when he was Izuku’s age—and presumably younger. So, Izuku was leaning more toward the instinctive knowledge theory. Maybe with some additional research to boost his efficiency. Then there was the mental communication component, and if his hazy memory was accurate, some degree of immune modulation to allow their bodies to mesh without suffering a catastrophic immune response. But how had the villain been able to fit—
Izuku was jostled from his train of thought by a mental nudge. “Jeez, kid. Your brain never stops, does it.” It was more an observation than a question.
“S-sorry. Did you hear all of that?”
“Nah, just the really loud bits. Unless you’re thinking ‘at’ me, I don’t hear your thoughts word for word.”
Izuku took his return to the present to register what his body was seeing again, a little disconcerted by how easy it was to completely block out the stimuli when he wasn’t in control. They were off the train now, walking down an unfamiliar street. This town seemed a lot smaller than Musutafu, judging by the lack of high rises, and it was a little after sunrise. He grew uneasy, thinking about what the villain intended to do with him. Was he finally going to kill him? Dump his body somewhere no one would ever find it? His mom would never get closure if that happened. Oh no! His mom! She must be worried sick by now…
His body chuckled before giving a wet cough. “Wow, you can work yourself up quick. I told you to relax, and I meant it. You kept your end of the deal; I’m keeping mine. Even if you don’t seem to include yourself in ‘don’t hurt anyone.’”
Izuku wasn’t really sure how to respond to that. He distantly heard grumbling—maybe an overheard thought like the villain had mentioned? “I might be a monster, but even I’m not going to kick a dog when its down.”
Izuku wondered if he should be offended by that.
Then there was a much clearer sigh in his brain. “I’ll make sure to leave you somewhere you’ll be found and given medical attention. Until then, I need you to sleep again. Can’t have you overhearing where I plan on going, now can I?”
So, Izuku had overheard one of the villain’s thoughts just then. Why hadn’t he overheard anything else? Was he too distracted by his analysis earlier, or was the villain better at shielding his thoughts due to experience? Maybe the strain of keeping his possession up so long wore at his mental barriers? Izuku had to have been taken at least 16 hours ago if the sun was already up.
Izuku felt a steady push at his mind, and his anxiety spiked. He didn’t fight it, but he did wonder if he’d really wake up this time as he went under.