After the momentary shock of being merged with his new friend, Bakugo Katsuki, Midoriya Izuku felt something he never thought he'd experience again: Satiated.

No longer was pain controlling each and every action of him, gone was the constant reminder that he was slowly dying and that he was forcing himself not to feel full, gone was the whispers of agony that tormented him when any organic wandered too closely.

His head was quiet now, quieter than it had been for a long time now. He could hear the birds chirping, the cars in the distance honking and yelling at each other, the water rushing onto the streets from the broken fire hydrant nearby. Midoriya was at peace, practically on cloud nine with how "full" he was.

And then he remembered exactly why he was feeling full, and remembered exactly why the fire hydrant was broken in the first place. His happiness died down in an instant as if it were never there; replaced with a sense of overwhelming guilt and sickness and disgust towards himself.

While Bakugo had nearly died and most likely (at best!) had a concussion from the impact, the slime teen was practically celebrating on having a "meal". "What kind of person does that?! He never gave me permission so I should...I should..." Izuku hesitated, wanting to do the right thing, no matter what his body told him to do. "I haven't felt this way in so, so long. Maybe...maybe a couple more seconds wouldn't hurt, right?" he asked himself, desperately trying to justify this horrible selfish act. He knew it was wrong, but it...it just felt so good not having to feel pain anymore!

"Okay, come on now, Izuku! Self control...self control. Five, four, three, two...one-"

Before Midoriya could finish counting the sound of metal bulging under immense force interrupted him. Stealthily, the slime-user commanded his quirk to send/form goo on the back of one of his friend's hands. The slime coalesced together into a near-perfect orb, with a bulge at the front that faces Bakugo's knuckles. Slowly it began to change pigmentation, turning from a lime-green color to perfectly imitate the sclera of his new host. An eyeball with a red iris now laid on the back of Bakugo's left hand. It blinked hesitantly, testing out how comfortable it was. Now able to see, Izuku could finally see that the stolen(?) car had crashed into a fire hydrant right after missing Bakugo, causing the surrounding area to be drenched in water. The driver of the car had his head buried in the emergency air bags, barely saving his life as he wasn't wearing a seatbelt. But all that paled in comparison to what, or rather, whom was staring down at him from atop the ruined car: The Number One Pro Hero himself, All Might.

"Have no fear, because I am here!" came the booming laugh of the Number One Pro Hero as he fell from the Heavens, landing safely on the destroyed car; it caving in further due to how heavy he was. All Might looked around after not hearing the usual response to his catchphrase, putting a hand over his eyebrow to get the glare of the sun out of his eyes. "I could have sworn I saw a young child earlier before," he thought aloud as his eyes casually raked over a fallen teenage body. Doing a double take, All Might's eyes bugged out of his head. "NOOOOOOOO!" shouted the buff man, guilt and regret surging through him as he jumped over to the blonde. After looking over the boy's body to see if he was breathing, a sigh of relief passed out of the Pro's lips when he noticed the rhythmic rise and fall of the blonde's chest. All Might fell down to the ground, breathing heavily after he realized he held his breath out of fear. He was so worried that the child...well, it doesn't matter anymore! The child, while banged up, is safe and not...not dead.

With a quick shake of his head, All Might crouched down next to the fallen teenager, before doing the next logical thing: Lightly slapping him on the back repeatedly. After a solid five seconds of this, Bakugo Katsuki awoke with a start. His head was killing him and he felt hungry. Why? "The fuck happened...?" he asked himself as he stood up, stretching his back as he hissed out in pain.

"Are you alright, citizen?!" came a booming voice from behind. Yep, he definitely had a concussion and that damn voice was not helping.

Feeling woozy, Bakugo turned around clumsily as he stumbled over his feet, ready to beat the ever living shit out of the one who was screaming when he came face to chest with his favorite Pro Hero. He craned his neck upwards, his mouth dropping. "No fuckin' way! ALL MIGHT?!" Katsuki asked incredulously, wiping his eyes with his hands to make sure this wasn't some weird fever dream.

"Ha ha! Yes, it is I, All Might! Are you okay, young man?" the Pro Hero asked, his bright blue eyes scanning the youth's body for any signs of trouble.

Bakugo blinked back his shock. All Might was worried about him? His cheeks felt slightly warmer. "Tsk, 'course I am. I'm made of tougher stuff," he confidently remarked, ignoring the way his skin seemed to be vibrating in excitement. It's probably just his nerves getting to him.

"Hmm, if you say so," All Might shrugged, putting his hand under his chin as he thought. "Still, I don't know what I would've done if things ended more on a sour note," the towering man gravely whispered, trying to ignore the newest nightmare he'll most definitely be having. "Say, do you want anything from me as an apology? A picture, perhaps? Maybe an appearance at your birthday party?" the buff man asked, the last part coming out as casually as discussing the day.

The explosive blonde's brain stopped functioning, his mind racing with all the countless possibilities. A picture with All Might?! Or maybe an autograph?! Why not both?! "I'd like..." he paused, thinking. The feeling of pity swelled inside of the teenager again that day, with the same intensity he felt when he met Midoriya today. "Actually...do you mind finding a weirdo I met?" Bakugo asked with a(n) embarrassed frown.

"Of course I'll do that, one photo coming right-wait what?" All Might was very confused, as he wasn't expecting that response at all. He was expecting to do the aforementioned photograph, an autograph, the birthday party, hell, some of his weirder fans asked for his hair once (he refused, of course). But this was new.

"He's this lime-green slime fuck that I met near the Eagle Diner and Aldera Junior High. I think he may be homeless, and...I'd like you to help the nerd out, okay?! He owes me because he ate my favorite burger!" Bakugo shouted, turning away as he crossed his slightly bruised arms in a huff, trying to ignore how his cheeks felt like they were on fire.

All Might brought his hand to his mouth, trying to stifle a chuckle. "I'll see what I can do, Young...?" Yagi paused, realizing he never asked for either of the boy's names.

"Bakugo. Bakugo Katsuki. And before you find that loser for me, his name is Midoriya Izuku."

The explosive blonde limped slightly as he slowly made his way home. His everything hurt, especially his left knee as it was already black and blue. "Fuck this god damn pain!" he growled out, wanting it to heal already.

Unbeknownst to Bakugo, Midoriya listened to every word in fear. He didn't mean to still be an unwanted passenger, but then All Might interrupted him before he left, then he fanboyed out at the hero's appearance, then he heard/saw Bakugo call him a friend, and then..."Those are excuses! This is wrong, I should just leave already! But...before that, maybe I can help first?" Izuku thought as he did his best to analyze his friend's body. Since he was connected to Bakugo, he could feel all his pain if he wanted to, and as he did that he immediately shuddered within Katsuki's body, the host's skin tingling in real time. Midoriya cringed before he decided to tell Bakugo's brain to ramp up the production of stem cells, fibroblasts, endothelial cells, and macrophages, all necessary for the healing process. So far, part of the frontal bone was fractured, as well as numerous other body parts. It'd take some time (and A LOT of effort), but the slime was willing to heal his friend to completion.

For Bakugo's sake, of course.

Halfway home, the hurt blonde realized he was walking normally. Not limping, not almost walking, he was genuinely putting his weight on his damaged left leg like he never hurt it. Confused, Bakugo stopped mid-stride and pulled up his left pantleg, gobsmacked when he saw clean unblemished skin. He touched his knee hesitantly, finding the skin to be soft and smooth, no pain whatsoever. His mouth in a slight 'O', he itched his hair in disbelief before he also noticed his headache was gone. "The hell? What the fuck?" he mumbled, shaking his head as he continued his walk home. Upon walking in, he went straight to the kitchen to grab a glass cup, downing the water as quickly as he filled it to the brim.

"Since when was I so thirsty? It's like I exercised too hard," Bakugo thought as he downed two more full glasses of water, his throat finally feeling better. He took a moment to breathe, finding it hard to believe that he didn't feel sluggish from the copious amount of water he drank in such a short time. Katsuki put down his cup, staring down at his hands. He flexed them into fists before releasing the muscles, wondering why he felt so good, so strong. Just ten minutes ago he felt like shit, barely able to move; but now he felt better than ever.

"Got a hand fetish now, brat?" a womanly voice asked as she ruffled his hair, a hint of teasing mixed in slight fondness as she asked it. Looking up, Bakugo saw his mom (Bakugo Mitsuki) looking at him in pride.

"Eww! Of course I don't, you old hag!" Katsuki barked out, ready to escape his mother's imminent rage at any moment. The punch to his head never came, as instead Mitsuki hugged her boy from the side, greatly confusing him. "This day is getting weirder and weirder."

She released him from the hug, rolling her eyes as he scampered away to the edge of the kitchen like she had a virus. "I heard you made a friend today, Katsuki. I knew you had it in you," his mom lovingly said, smiling as some of her stress went away. She was worried that this day might never come, as her son was a spitting image of her when she was younger. But the day had finally come and it made her so proud.

Bakugo blushed, annoyed that it was becoming a trend today. He tsked loudly, trying to come up with a good way to escape this embarrassing conversation. "Whatever. What are we having for dinner, hag?"

Mitsuki scrunched up her face, annoyed that her son was still disrespectful to her. "You're lucky I'm in a good mood today, brat. I was thinking katsudon," she mumbled, looking in her fridge to find any pork she could use.

The younger blonde rolled his eyes at the suggestion, as his mom had been pushing for him to try said meal since forever. Right before he told her to fuck off, Bakugo felt his skin tingle with excitement, the hair on his arms pointed outwards as if he got goosebumps. Katsuki knew everything happened for a reason, that things happening multiple times in succession was a pattern, not a coincidence. So he found it very odd and very strange that this had happened to him not once, but twice the same day. First with All Might and now with katsudon. When you combine those two instances with his new inhuman healing Bakugo scrunched his eyebrows in suspicion. He shrugged in forced nonchalance as he quickly said, "Sure, I'm going upstairs. Don't bother me."

He didn't wait to hear his mom's surprised gasp as he ran up the stairs, two steps at a time. He practically slammed the bathroom door open, quickly closing the door behind him. The bathroom was a mess, beauty products haphazardly strewn about. Various mascara wands littered the ground, making the tiled floor a minefield for him. He swept them out of the way with his shoes, trying to not swear up a storm when the mascara marred his nice shoes. After an annoying five minutes of cleaning his mother's mess up, Bakugo Katsuki stared long and hard at his reflection in the mirror in scrutiny. At first glance everything appeared to be in order. He had two eyes, one mouth, and a pimple on the underside of his chin.

That last one was entirely the problem. With no hesitation Bakugo pinched the pimple off, watching in disgust as it reverted back into lime-green slime before it reabsorbed back into him (without his consent!) through his fingers. He grinded his teeth in anger, feeling betrayed. He stared hatefully at his own fierce red eyes. "Get off. Now," he commanded in fake calmness, hoping to the high Heavens that the stowaway was compliant.

He saw but more so felt the left side of his body become gooey as Midoriya Izuku detached himself fearfully from his former host, the look of guilt clear as day on his face. Bakugo noticed that his acquaintance...no, his former acquaintance looked healthier than the last time he saw him. Midoriya's eyebags from earlier were gone and he had more slime on his nonexistent bones.

"W-w-w-wait! I can e-explain!" the slime teenager stammered out quickly, manipulating his body so that he gave a perfect 90° bow. If Izuku could sweat he'd be flooding the bathroom by now with how scared he was. He closed his eyes, waiting for the punch, the kick, or even bite that may come. He deserved it, of course.

"Really? You've got ten seconds before I grind you up and sell you as lime Jell-O, you bastard," Bakugo threatened as he raised his hands to attack, making tiny pops and crackles in preparation.

Midoriya got out of his bow in haste, his eyes shooting open before saying, "I-I didn't mean to! The car-if I didn't, you...you," the slime boy stopped talking when he realized that his voice was too wobbly to continue. After a moment of silence and being sure he could talk (for the next few sentences or two), he quietly added, "I couldn't just watch you die."

Bakugo's face softened by a smidgen as he blinked in surprise. "Wait, this fucker saved me?!" He shook his head, his anger coming back in full force. "That doesn't explain why you're here, asshole. Or why you were hiding inside me, you god damn parasite!"

"I merged with you...by mistake, of c-course! And then...and then I got selfish," Midoriya softly admitted as he hung his slimy head low, ashamed of his actions. "I...I didn't want to tell you but...I don't eat food in the traditional sense. You're right, I pretty much am a parasite," he admitted solemnly, exhaling an unneeded breath upon finishing.

The blonde raised an eyebrow before he slowly put down his hands as he instead crossed them over his chest. "Slime boy here was skinny looking before he apparently saved me. Now he looks healthier after spending some time on me and to top it off he apparently 'merged' with me...of fuckin' course," Bakugo finally realized what Midoriya was hinting earlier. A frown replaced the scowl on his face as he bluntly asked, "You need a host to survive, don't you?" Most of his fury dissipated when the explosive blond saw Midoriya glumly nod.

Great, now he felt like an asshole.

"Uh…I know it's n-not the time, but, um, how's the leg?" Midoriya meekly asked, blushing a darker shade of green as he asked.

"It feels fine, nerd...wait! Did you heal me earlier?!" Bakugo asked excitedly, forgetting his earlier anger at the moment.

"I-uh, yes? You were in pain, so I just wanted to help. Sorry if I overstepped any boundaries!" Izuku rushed, looking more worried than before until he noticed that Kacchan had large saucers in his eyes, as if he was impressed by the slime. Bakugo quickly dispelled it however, adopting an uncaring look instead.

"Tsk, it's fine, you fucking nerd!" the blonde yelled, making Midoriya literally shrink into himself a little. "What else can you do?"

"A lot? Maybe?! I don't know, I've never really t-tested it before," Izuku admitted as he sat down on the nearby toilet seat, feeling embarrassed from all the attention.

It felt nice though.

Unbeknownst to the slime Bakugo was thinking devilish thoughts, "Not only can this nerd heal people faster, but I have a feeling he can do even more, if only he had the right 'push'. If I had him on my side and I push his buttons in just the right way…I'd be the Number One Pro Hero in no time." he thought, a smirk appearing as he thought selfishly. "So? Test it out now, you slimefuck," Katsuki commanded as he sat down on the sink countertop, holding out his left hand towards the greenette.

To be clear, Bakugo didn't actually want to extend his hand, just like how you don't want to take a loan. But in his mind the risk far outweighed the possibility that he might very well lose his life from this exchange.

"W-wait, w-what?!" Midoriya stuttered as he stared longingly at the hand. The entirety of his slimy body was telling him to latch onto it and never let go, but it had to be a trick. Izuku looked up at Bakugo, who gave him a simple nod. Despite his reservations, Midoriya touched his friend's hand before he quickly started to seep into the skin through the blonde's pores. Entranced, Katsuki watched as he felt and saw the wet and slightly cold feeling of his acquaintance entering him before the slime disappeared, leaving him 'alone' in the bathroom.

"Ahh, much better," Izuku sighed contently, his hunger dying (for now).

"How can I hear you if you have no mouth?" Bakugo asked, looking around the room/himself. Suddenly, the slimy green head of Midoriya popped out of the blonde's abdomen like a chestburster, which would've scared any normal person if Bakugo hadn't felt the area of skin tingle before his friend popped out. The two stared at each other, waiting for the other to make the first move. "Are we gonna test it or not?!" Katsuki gruffly reminded, tapping his foot impatiently.

"I-I guess I'll start with your hands?" Midoriya suggested. Immediately, Bakugo felt something sprout out of his left hand. Bringing the aforementioned hand to his face, he saw a peculiar (yet also strange and horrifying) sight: He had eleven fingers. A second pinky finger, which was even smaller than the original one, was now on his left hand.

Hesitantly, Katsuki tried to move it.

It moved. It moved! His new sixth digit moved and felt like he always had it. His jaw dropped, smiling in awe. "Woah! This is fucking awesome, if a little useless," Bakugo praised, clenching and unclenching his hand in amusement. It was comparable to a child being amazed by a game of peek-a-boo.

"Not as useless as this," Midoriya said before he sent his slime to envelop Bakugo's hand. Entranced once more, Bakugo watched in confusion as he saw a tiny slime pimple (the size of a dime) sprout out the back of his hand. If that were it, then it would've been fine.

But the pimple ballooned to an obscene size, growing until it was twice the length and weight of the hand it was on. The pimple then began to morph and grow in very specific directions until finally it resembled a crude left foot. The crudeness would not last long, as the slime turned into bones, which got covered by newly made muscles, and then was covered in skin, the latter of which changed to the same pigmentation of Bakugo's own skin color.

Toe nails, hair, callus and the like; it was an exact replica of his left foot. Blinking in morbid curiosity, he tried to wiggle his newly acquired toes.

It worked.

That entire science fiction-like process took less than thirty seconds, and the newly added limb worked as if it had always been there, just like the pinky that came before it.

"Now this is useless," Midoriya stated, something akin to smugness in his voice oddly enough.

"That should've hurt..." Bakugo commented in slight horror, twisting his new foot-hand to look at it better. If he didn't know any better he would say that he was looking at his real left foot, as he could see his ankle bone and everything else a foot should have.

"I turned off your pain receptors for your hand temporarily," Izuku casually explained as his head moved from Bakugo's chest to his left elbow, inspecting his handiwork. "S-sorry that I did that without asking, but I thought you wouldn't like how it felt…"

"I w-want my hand back," Katsuki pleaded commanded, failing to keep the fear out of his voice. Izuku listened to the order quickly, restoring his host's original hand by transmuting the foot part back into slime. The slime formed a small face on Bakugo's palm, an apologetic look on his mini face.

"S-sorry about that! I didn't mean to scare you. Please forgive me!"

"It's-"

"I swear, I won't do it again! I promise!" Izuku continued on, not hearing that he was already forgiven.

"I said it's-"

"You've been so nice to me, and then I overstepped a b-boundary! I'm-"

Agitated that he kept getting cut off, Bakugo decided to activate his quirk in his left hand, hoping to shut up his friend. It worked, as Midoriya stopped talking as he exploded off into Kacchan's face, effectively blinding him. Holding back the scream he so desperately wanted to let out, Bakugo waited for his acquaintance to regress back inside him before speaking:

"I'm setting some ground rules."