When he lost the fight against Overhaul, Deku had expected death. In retrospect, he probably should have begged for it.
They took away his Quirk, locked him in a cell, seemed to entirely forget about him. He couldn’t tell the passage of time, but the periods in between being brought food and water were long enough to leave him weak and shaking. Worst was the boredom. With nothing else to occupy it, his mind began a slow spiral of despair. When Overhaul started visiting him, it was a relief.
He measured Midoriya, took his weight, his height, his circumference, wrote it down in a little notebook. When Midoriya dared to ask what it was all for, Chisaki removed one glove, took him by the throat, rearranged his vocal chords so that all that came out when he tried speaking was a garbled mess.
Midoriya didn’t speak. Didn’t try to anymore, just eyed Overhaul warily every time he came in, waiting for the other shoe to drop. Because of course Overhaul had something awful in wait, of course he wouldn’t be content to just run a tape measure around Midoriya’s waist and call it a day.
So when Overhaul reached down and started jerking him off, Midoriya couldn’t even say he was surprised. Horrified, sure, and he did his best to fight back, but Overhaul made threats, asked him what he’d look like with no arms and legs, wrapped his fingers menacingly over Deku’s face, terrified him into cooperation. Midoriya knelt with his legs spread and tried not to think about it. Just let it happen, tried to take the stuttering orgasm that came as some sort of relief.
Overhaul timed him. Because of course he did. He kept a stopwatch, measured Midoriya’s orgasms. Caught his release in a cup and measured that, too. This went on for a while, however long Overhaul needed for his little science experiment. Then one day Chisaki wheeled in a cart, filled to the brim with all sorts of medical equipment, and said, “We’re moving on to stage two. Get on the bed.”
By now Deku knew better than to refuse. When Overhaul got out restraints and strapped him down, his only thought was a vague I can't stop you, so it's not like I'd bother struggling. That was soon proven false. Overhaul brought out medical wipes, started sterilizing his junk, rubbing along his inner thighs and over his perineum and around each ball, and Midoriya couldn’t help but panic a little. He let out a groan, the most his ruined throat could managed, and strained against the cuffs. Chisaki acted like he didn’t even hear him. He snapped one glove off, and that was when Midoriya knew he was really in for it. Even when masturbating him, Overhaul always kept his gloves on. That hand meant change. Unnatural, unavoidable change.
Midoriya trembled and cried, but he couldn’t do anything. He felt a hand, icy cold and bony, cradle his testicles, and Midoriya had to resist the urge to piss himself in fear.
It hurt less than he expected. Maybe that was the power of Kai’s Quirk. There was no cutting or ripping involved, just a flash and a sound like wet meat falling to the floor. Deku felt the loss immediately, the weight falling away as his nether region becomes marginally, horrifyingly lighter. Deku’s eyes were screwed shut, blinded with tears, so he didn’t actually see what Overhaul slid into one of the little jars on the table, only heard a wet plunk, and by the time he opened his eyes the man was screwing the lid back on.
Overhaul untied him, left him to his own devices again. Immediately, Midoriya’s hands were on himself, feeling the space between his legs, the unexpectedly smooth gap where his balls used to be. Now the stretch of real estate between his asshole and penis was unoccupied.
Don’t panic, he told himself. You can survive this. At least he didn’t take your dick.
But soon the full extent became apparent. Their next session of Overhaul jerking him off and Midoriya obediently staying still and letting it happen didn’t end in orgasm. Only tears of frustration from Midoriya, who can’t even get it up, remains soft and limp in the man’s gloved hand. For his part, Overhaul looked unaffected. He just continued to watch Midoriya with passive eyes, cooly observing as the boy slowly broke down, frantically humping into Overhaul’s clenched fist in a way he never had before.
After Overhaul was satisfied with the results (or perhaps too bored to continue), he left Midoriya behind in the cell. The rest of that evening, Deku stroked his dick like one would a terrified animal, begging it to be okay, pleading with it to work, trying to coax it to life. Nothing.
This continued for a week, Midoriya getting more desperate each session. Whereas before Overhaul’s attentions only brought him horror, now Midoriya begged for them, spreading himself wide when the man entered the room, hoping maybe his touch would magically cure what was wrong with him. It didn’t. There was a light at the end of the tunnel, though, because on the seventh day Overhaul returned with the cart. Midoriya was on the bed without even needing to be asked, eager for what he assumed was the replacement of his dearly departed family jewels.
Again the restraints came out, and again Midoriya didn’t resist as he was tied to the bed. He had to resist wiggling in excitement as Overhaul cleaned and sterilized him, his body a chorus of anticipation. Chisaki unscrewed a jar, pulled out a lump. Midoriya was too elated to process the flaw, his brain recognizing a familiar shape and not noticing all the ways it was slightly off. Before he could, Overhaul pressed it to him, there was another flash, not painful but unfamiliar.
Still, when the weight settled Midoriya let out a relieved sigh. It sat so heavy between his legs, like a cat curled against his side, warm and firm and oh god he had missed having testicles. When Overhual let him up, Deku swore there was a ghost of amusement in the man’s normally flat expression.
“Don’t get too ahead of yourself,” he instructed. “Stage three starts tomorrow.”
Then he was gone, and Midoriya was left to slide himself off the bed and...oh.
Something was off.
His dick looked half erect, as if celebrating the return of its brothers. But looking down, Midoriya realized that no, it was simply being propped up by the now massive pair of balls sagging from his front. His first response was confusion, then anger, than horror.
He put the wrong fucking pair of balls on me!
Indeed, as Deku probed the protrusion, he couldn’t even be sure Kai had gotten the species correct. He’d never seen a human walking around with something as massive as these. They weighed heavily, pulling on the nearby skin in a way that was almost painful. The color was close to right, a few shades pinker than he was used to and smooth, almost close enough to pass except for their proportions. A few cursory steps revealed that they smacked painfully and risked getting caught between his thighs. It was easier to sink down to all fours and let them droop forward.
Deku spent that night lightly exploring his body, trying to convince himself that it was okay, maybe it wouldn’t be so bad, he could pass himself off as normal when he got out of here. Who cared if his cock was now absolutely dwarfed by the duo of grapefruits adorning his pubic region? Surely he could still lead a full life.
Again, his idealism met a hard brick wall the next day. Overhaul jacked him off again, stopwatch in hand. Even though Deku didn’t see the numbers, he was sure they were impressive. Because his orgasm started and it...just didn’t stop. He couldn’t hope to keep track, not with the thundering in his ears, but he could tell that it wasn’t normal. By the time he finished, finally came down from the tidal wave of release, the little measuring cup Overhaul brought for his ejaculate overflowed, dripping a staccato rhythm of spunk onto the floor. With a hiss of disgust, Overhaul dropped it.
“I’ll need a bigger container,” he muttered to himself.
Still Midoriya clung to hope.
Maybe I was backed up. Maybe it will be more normal next time.
No. If anything, next time was worse. Overhaul brought a bucket, placed it between Midoriya’s legs and jacked him off into it. This time, Midoriya tried to keep count, marking time by the pumps along his dick after he started releasing. He lost track around thirty.
There were other changes, too, ones that reared their head slowly over time. For one, every week or so Overhaul had to reexamine him, use his Quirk to keep the terrible transfusion in place. It was like his body knew how revolting this was, tried to repel the unwelcome intrusion with rashes and sores, but Kai’s hands on his body put him right again.
Another change was the hair. Distantly, Midoriya thought maybe his body was getting too much testosterone now, the oversize testicles producing a bumper crop in the form of fuzz. Fields of coarse green hair sprouted across him, and his happy trail becomes an airplane landing strip. Would he be worried by it? Maybe, if his sex drive hadn’t cleared out most of his rational thoughts.
Overhaul’s daily sessions weren’t enough for him anymore. Every few hours his body burned with need, and he couldn’t think of anything until he had found release. Between the frequency of his arousal and duration of his orgasms, he spent half the day in a blissed out state, hips stuttering and twisted throat moaning. At least that way, he didn’t have time to think about it all, about what he’d become. Sometimes in the post-cum clarity it would sneak up on him, and all he could do was return his hands to his dick and chase away the horror with the sound of wet slapping.
He had no idea how long he’d been here, caught in the cycle of fucking, sleeping, eating. Long enough for Overhaul to get the data he needed. He came to Midoriya one day, and again a telltale trace of amusement graced his features.
“It’s time for stage four,” he said. “Come on. Let’s introduce you to your gilt.”