The anime left off at such an awkward point and the smart thing to do would've been waiting until it was covered in full in season 5 to include it, but when have I ever been smart? So yeah,,, I just dipped into the manga to get the details and wrote out the scene. I was really excited to include this idea, okay ): It may have messed up the already fucked timeline by including it here, but honestly??? Who cares!! We're havin' fun in this fic tonight, ladies!

so yeah, beware manga spoilers ahead

Anyway, take care of yourselves, you know the drill. Enjoy the chapter!!

Discord server, if you're destruction, decay and desire: https://discord.gg/DSBF4dP

~

Izuku rubbed at his aching shoulder, letting out a sigh as he trudged along. His whole body was sore and his muscles had definitely been torn in his reckless fighting against High-End. The chaos had drained him, but he couldn't find it in himself to regret reassuring all those terrified people.

He forcefully straightened up, pushing his shoulders back and raising his chin to walk with confidence, ignoring the sparks of pain in his joints with every movement. It would likely fade after a good night's sleep, and if it didn't, then he'd go check in with Recovery Girl. Right now, he just wanted to go home.

Faint light spilled across the gate, cast by lamp-posts lining the front path of UA. Three figures stepped into the entryway, and after a tense moment of panic, Izuku recognised them easily and offered a wave whilst mentally preparing himself for the scolding of a lifetime.

"Midoriya," Aizawa greeted flatly, his arms crossed and his hair tied back.

"Sensei, good to see you," Izuku responded cheerfully, offering nervous finger-guns and glancing at the other two adults lurking. "Toshi-san, you're looking well. Mic-sensei, I almost didn't recognise you with your hair do-"

"Don't try to change the subject," Aizawa cut in, stepping in the way when the boy tried to slip past.

"I followed your rules," Izuku started hesitantly, then mentally shook himself and steeled up. "I asked for permission earlier, and I warned you before I left. There was no League directly involved, and it wasn't a particularly dangerous mission, and I had the support of other heroes on scene. I understand you're worried, but there's no need to berate me every time I step in, because – I mean, really, I'm always gonna throw myself into fights to help people, and you'd run out of breath before you finished scolding me."

"My boy-"

He gently pushed past his mentor, rubbing his face with a hand. "It's not something you're going to stop me from doing, which I thought we'd covered last time. I'm sorry for stressing you out, but I'm technically a Pro Hero – and nearly your age, Aizawa-sensei, Mic-sensei – so fights like this are part of the job, no matter that I'm somewhat limited by my younger body. Besides, the new suit is a whole lot more supportive, and my Quirk didn't even hurt me, even when I used it at higher levels to dodge safely."

"Little listener-"

"I get your fear, I really do – the amount of times I've seen my friends go out and fight when I'm not there to help... It's really stressful, but I know their capabilities, and I have faith that they can handle it. I know I can't be everywhere at once, or help everyone who needs it, which is precisely why I need to step in when I can in fights like these, because I know I can support people in need, and ensure things change for the better, regardless of if it went well enough last time or not. My power and experience isn't something I want to waste by hiding away," he rambled as he continued walking up the path.

"Problem Child-"

"I truly am sorry for making you feel bad, but I can't let civilians remain in fear when I know I can do something about it. Offering comfort and hope is something I'm good at, especially in times of crisis. I barely even intervened in this fight because it was important for Endeavour to prove himself to the world, so I focused mainly on soothing the scared people – because I hate the thought of people being scared, and I want to let them know it's okay, because I am here, and I can't really do that as myself, but-"

"Izu."

His head snapped up. Inko was standing just ahead of him, warm light haloing her form. She was fiddling with her fingers and looked immensely nervous, her bright eyes glistening. Tear tracks were visible on her cheeks, and Izuku's heart broke.

"Mum," he breathed, hurrying towards her and gently placing his hands on her shoulders. "I- I'm sorry, I didn't mean to worry you, I just-"

She let out a soft sigh, relaxing marginally under his touch. "I- I know, Izu. You're a big brave hero with people to save, and it would be selfish to tell you to stop just so I could feel better, but..." She exhaled again, shaky palm reaching up to cup his cheek as tears welled in her eyes again. "I can't help but look at you, and see my baby boy. A-And, you may nearly be thirty, b-but... you'll always be my son, and I want you to be safe."

"Mum-"

"I know, I know... I want you to be safe, but I also want you to be happy. A-And I know you won't be happy if we keep telling you to stop, so... I'll keep supporting you, Izu. I promise," she finished quietly.

Izuku sniffled, then pulled her into a tight hug, tucking his head next to hers and burying his face in her hair. She smelt like home, and his throat tightened. He dug his fingers deeper, clutching desperately at her soft cardigan.

"N-Now, I'm sure your friends are worried about you too," she said, pulling away and fixing him under a firm, if tearful, stare. "Go and see them, and then go to bed. You must be exhausted."

He gave a sheepish nod, rubbing at his eyes with his sleeve and sniffing a final time to regain his composure. "R-Right. Okay, mum. I love you."

Her expression softened with fond pride. "I love you too, Izu."

Izuku glanced over his shoulder just in time to catch Aizawa and Mic exchanging faintly pained looks. Mic silently brushed past, offering the boy a small smile before guiding his mother away. Toshinori padded up to stand next to his successor, gaze gentle and tired, but brightening marginally when Izuku automatically tucked himself under his mentor's arm, posted protectively next to the wound on his left side.

"Y'coming, sensei?" Izuku inquired from where he was comfortably nuzzled.

Aizawa hesitated, then eventually shook his head. "No, I've got to... Rethink my life choices."

He winced guiltily. "Yeah, sorry, that happens a lot when I'm around. Have fun, sensei. Goodnight, if I don't see you again tonight. Oh – could you text Ragdoll-san and tell her I'm sorry and I'm okay?"

The teacher turned around and trudged up the path, offering a brief splay of fingers that could be considered a lazy wave. Izuku blinked up at his mentor, smiled warmly, and the two of them started padding across campus towards the 1-A dorms. Lights still shone in most of the common room windows in each dorm building, emphasising how many people would have likely watched Endeavour's live fight.

"My boy?" Toshinori spoke up softly.

"Mm?"

"You nearly gave me a heart attack when I saw you on TV-"

Izuku winced again. "Sorry."

"But I wanted to say... I'm proud of you, Young Izuku."

Izuku's face scrunched up as his heart squeezed, and he let out a muffled sob, burying his face in the crook of his elbow and wrapping his other arm around his face as he tried to get a hold of himself – but All Might told him he was proud! Of him! Him, Izuku! That warranted a little ugly crying, in Izuku's opinion.

"Ah, why d-did you have to say that n-now, we're right at the dorms, how am I gonna m-maintain my cool, bad boy reputation if they s-see me crying-" He wailed into his arm.

"I-I'm sure they'll understand, my boy," Toshi responded in a voice thick with suppressed laughter, a large palm gently patting the boy's back supportively.

The front door swung open, sending yellow light spilling across the porch. Izuku hastily wiped away the evidence of his tears and grabbed a packet of gum from his shorts, placing one piece into his mouth to chew nonchalantly. Ochako and Shouto were at the front of the group, staring at him with wide eyes.

"Hey," Izuku greeted, tucking the gum into his cheek.

"Where were you?! You missed all the action, dude!" Kaminari exclaimed from somewhere at the back of the group.

"I bought some gum," he answered, offering the packet. "Want some?"

"You bought some-" Ashido pulled a face, then snatched a piece for herself- "Yeah, I do. Thanks, Midori!"

Most of the others dissipated back to their seats in the common room. Kacchan gave him a once-over, glowered harder, then grabbed Eijirou and stomped away with him whilst the redhead waved. Shouto hesitated, then stepped forwards and awkwardly extended his arms and wrapped them around Izuku in what was simultaneously the best and worst hug he'd ever received. Izuku leant into it with a soft smile, patting his friend's back and revelling in the unique hot-cold experience that brought a wave of homesickness he buried deep in his chest.

"Are you okay, Deku-kun?" Ochako asked quietly, reaching up to lightly touch his shoulder.

"That fight was really scary," Tsu added, sharing a worried glance with her friend.

"I'll leave you to it," Toshinori murmured, ruffling Izuku's hair and padding away.

"The villain was so powerful," Momo commented. "Would you like some tea, Izuku-san?"

"It was worrying to see you appear so suddenly on the battlefield," Tenya said, and Kouji rapidly nodded his head, Yuwai clutched to his chest.

"Sorry for worrying all of you," Izuku mumbled into his friend's shoulder. "And no thank you, Momo-chan."

Shouto falteringly pulled away, settling back into an uncertain standing position. "You're not hurt?"

"No, just some pulled muscles, I think," he assured, raising his arm to examine it.

"Come inside, Izuku-kun!" Tenya ushered him in and closed the door behind him.

Izuku's gaze locked onto his jacket still on the coat-stand, and he rummaged in the pocket to retrieve his phone. He grinned fondly at his phone background, with him sitting on Toshinori's shoulders after plaiting his hair, pupils blown wide and expression slightly manic whilst Toshinori was mid-panic, reaching up to try and stabilise him before he could tumble to the ground. His hand had been shaking so much that the picture was blurry, only adding to the hilarity of the scene.

Leaning in close to take a quick selfie with Yuwai, he sent the picture to the group chat of everyone who knew his secrets, adding a quick message of reassurance so Hitoshi, Mirio, Tamaki, and Neijire wouldn't worry about him. He straightened up and slipped his phone back into the pocket of his shorts with the gum, flashing a grateful smile to Kouji, who returned it timidly.

"I'm, like, two seconds from passing out," Izuku admitted, only to hastily flail his hands in denial when several of his friends' looked alarmed – and with good reason, given his history. "I meant that figuratively! I'm just super ready to crash into bed! I'm okay!"

"Oh, alright then, Izuku-san." Momo breathed a dainty, relieved sigh.

"Get to bed, Izuku-chan," Tsu told him gently.

"Do you need us to do anything for you?" Ochako asked earnestly, gaining several nods of agreement.

He chuckled, warmth blooming in his chest at their concern. "No, no, it's okay. Thank you, though."

Izuku padded deeper into the common room, glancing over at where the rest of his class was gathered, all chatting away with lingering anxiety but mostly excitement. Sero looked over his shoulder and caught sight of him, then slapped Kaminari's shoulder to get him to turn around.

"You gonna join us, Midori?" Kaminari called, looking exceptionally hopeful.

"No, I'm gonna go take a hot bath, then do some yoga, I think," Izuku said, offering a smile and slowly padding towards the lift. "You're welcome to join me if you want, though."

"Join you in the bath?!" Ashido exclaimed, sounding far too interested in the offer.

Tenya rounded on her, chopping down a hand. "Ashido-san! That is hardly an appropriate-"

Izuku merely winked at her, resisting the urge to cackle as she let out a panicked squeak and shrank down. Kaminari's cheeks pinked faintly, and even Sero seemed taken by surprise, covering his mouth with a hand and nervously averting his eyes. Izuku hastily turned away and retreated to the safety of the lift, only letting loose his laughter when the doors had closed.

God, it was so much fun to tease them.

*

Despite being capable much harder training in the future, his current body was still far more easily exhausted than he was used it. Mere endurance training was enough to have him stumbling like a zombie back to his dorm room and face-planting into bed – although, to be fair, his basic training would be hell for anyone else. He fell asleep almost instantly.

And then...

The landscape was darkened. Shadows wreathed around, leaving only the immediate vicinity illuminated, revealing a cracked ground. He stayed still for a moment, vaguely aware that he was dreaming, but unable to shake the familiarity of the scene. Slowly, his eyes flitted sideways, and he tensed up at the sight of a line of figures to his right, only to freeze at the sight of Nana, and beyond her were the previous holders, including the misty figure of Toshinori.

Deku glanced down at his hand, lifting it up and examining his arm in a numb state of shock. He was wearing his hero costume – but not his current one, it was the one he wore in the future, the same one he was sort-of murdered in. The more he stared at himself, the more he realised he was taller and bulkier than he had reluctantly grown used to in his teenaged body, and he reached up to tug at a curl of his hair, confirming that it was shorter.

"Why do you stand against me? Join me in my conquest, my adorable, foolish younger brother."

That voice... His head snapped up to stare at the scene unfolding before him. Two brothers, both with white hair, one skinny and frightened but stubbornly refusing to give up, and the other stronger and neater, exuding an air of arrogant confidence as he calmly stood with his hands in the pockets of his suit jacket. Deku's heart stuttered.

One for All, and All for One.

"Because everything you're doing is wrong! And I can't possibly forgive you! Not a single fibre of your being!"

But, what-

This was something he'd already been through, right? He hadn't seen the vestiges at the Sports Festival because he'd broken out of Hitoshi's Brainwashing on his own. Had he been wrong to presume the other weird experiences wouldn't occur, too? Well, clearly – but why?

Gradually, the realisation dawned upon him, and he tore his gaze away from the stand-off to look to his left, meeting wide green eyes belonging to a figure mostly restricted by smoke, leaving only the top half of his head and one scarred hand. It was... himself. Well, his teenaged self – Izuku, he supposed. They stared at each other in identical states of shock.

Deku cupped his chin thoughtfully. Izuku followed the movement with his radioactive eyes, then raised his own hand, placing his thumb by his misty mouth to mirror the motion and squint his eyes in a nervous smile, gaining a grin from his older counterpart.

"What a terrible thing to say. And here I am, trying to compromise," All for One drawled, spreading his hands out to the side. "Isn't there even a tiny bit of open-mindedness in your so-called righteousness?"

Two sets of emerald eyes turned back on the scene. It felt wrought with lingering fear not their own. Deku spared another glance at the previous holders who all stood like statues, but the two at the end of the line were blurred out, which was weird because he had long since uncovered their identities, but-

He let out a soft breath of realisation, his arm falling back to his side. Of course.

First and foremost, this version of One for All belonged to Izuku, not Deku. They shared a body, but not a mind or spirit. The only reason he was able to use such a high percentage of the Quirk so rapidly was due to his own experience with One for All, but he was still limited by their body. It was unlikely that Izuku could handle any more than the original 20% on his own, the same as Deku in his original timeline – but he'd never thought to try and ask, since there wasn't an easy means of communication between just the two of them-

"The world has fallen into chaos! 'Superpowers' should not be used to fulfil your own selfish desires! You're not thinking of anyone but yourself!" One for All snapped back in a rasping voice tight with strain.

-or, at least, there hadn't been until now... What would this lead to? This was the first time they had been split into clear, separate entities in the same area. Deku looked at his younger counterpart, observing the way he watched in horror as All for One took one person's Quirk and gave it to someone else. The first holder collapsed onto his knees in defeat, face obscured by shaggy white hair. Another figure leapt in and slammed him to the ground, roughly holding him down whilst One for All weakly struggled, fingers digging into the concrete.

Izuku turned his head to Deku, eyes wide and desperate, his hand clenching towards the scene. Deku just shook his head apologetically, offering a half-shrug. There was nothing they could do to alter what had been done.

"Aah... you poor thing. How pitiful it is, to be born without a superpower. Without power, one cannot even assert their ideals..." All for One remarked with a fake sigh of pity. "Even so, I still love you, my pathetic younger brother... You're my only family, after all."

The flashback shifted. Tall buildings stretched up around them in the void. Scenes of violence played, showing both those with and without superpowers, and the one who ruled above them all with his unique ability. Slashing weapons and swapping superpowers, crowds of shadowed followers, a starving figure huddled in a locked room, a looming man in a suit and a half-concealed face...

"Fantasy has become reality!" All for One snarled, clamping his hand around his kneeling younger brother's face as his jaws parted in a scream- "And in reality, things don't go like they do in stories! And now, I'll rewrite the reality in which you refuse to yield to me!"

"Stop it!" One for All howled, clawing at his brother's unmoving arm.

Izuku desperately reached out his hand, and the scene dissolved into swirling smoke, sinking them back into the plain void once more. His wild green eyes locked onto Deku through the mist, and the hero, although shaken, offered a soothing smile and raised his arm to hesitantly brush their fingertips together. Emerald sparks fizzed off the point of contact, and both flinched away in surprise, only to slowly press their palms together, one hand smaller, the other weathered, but united by DNA and determination.

Two realities stared at one another, in awe of the impossible.

"This is strange..." One for All murmured in a high and friendly voice, stumbling out of the darkness, visible only in highlights. "Two ninth holders... I wanted to show you a little more, but... It seems that you can only manage about 20% right now. We've long since passed the point of singularity..."

The younger brother stepped up to them, slowly threading his slim fingers between both of theirs, warm and electric and frighteningly real. Deku and Izuku gazed at the first holder in stunned silence, and gradually, all their predecessors faded into focus, reaching out towards them with supportive expressions. His lips quirked up in a weak sort of smile that rounded his sallow cheeks. A faint breeze, ignited by their collective Quirk, ruffled his white hair aside just enough to get a hint of eyes squinting fondly.

"...but don't worry. You are not alone."

He jolted awake in an explosion of power and a hint of a final phrase ghosting through his mind.

"But you haven't been alone for a while, have you?"

Breaths came in panicked gasps. Magenta glittered over scarred skin. Fingers clenched into the torn mattress. The scent of ozone lingered in the air.

"W-What was th-"

A soft gasp. Glowing fingers hesitantly rolled into a fist, then splayed out on the pillow in a flutter of green sparks. Wide eyes roamed around the bedroom, taking in the destruction. Scorch marks, scrapes and scratches, torn paper, knocked over figurines and a tipped office chair, stuffing strewn across the floor from the shredded duvet and mattress.

Tensed muscles. The door was open. A panicked glance.

"A-Aoyama-kun-" Bare feet scrambling to press into the carpet- "I-I'm s-sorry, d-did I... Did I disturb y-you?"

Aoyama paused, the shocked look fading from his face as he raised to point. "Diet or non, you should stockpile cheese, mon ami!"

A glance at the glittering hand. "Y-Yeah, you're... You're r-right, um... Sorry to w-wake you."

The boy gave a hmph, hand twisting up to frame his face in an elegant pose. "Beauty sleep is important. Get some soon, hm? Bonne nuit."

"B-Bonne- um. Bye."

The door closed quietly. Aoyama padded back to his room.

A steadying breath; a puffed chest. One for All wouldn't settle easily. Memories of memories rolled by. Slightly crooked fingers violently ruffled through green curls. Teeth gnawed on a bottom lip. Sharp eyes examined a flexing hand.

"U-Um... future... me? D-Deku-san? A-Are you..." A shaking exhale; an anxious swallow. "Are you there? I-I don't know wh-what just happened, a-and I'm s-scared – I don't kn-know what t-to do – you always know w-what to do, pl-please, I-I need advice-"

There was a rush of soothing warmth, like an invisible hug. Tension flooded from stiff shoulders. Trembling eased up slightly, and One for All gave a final flicker before fleeing, settling back under skin.

"O-Okay, that was... That was you, right? Th-that means you're still here, so, u-um..." Arms loosely wrapped around in a comforting motion; a shake of the head preceding a determined expression. "Alright. I just need to work out how to... bring you back in control. And... If you're technically me, then... what would I do? This hasn't really happened before – there's only been the times when you went back to the future and I was left in control... But this is different, because we're both still here. I guess it's kinda similar to when you warned me before leaving after the fight against Chisaki, right? And you just sort of... reached out to me? Mentally? Somehow? And I could prepare to be in charge again, so, uh – oh! It's like turning food around in the oven to make sure it all gets cooked evenly, right? It gets flipped or moved to the front or back... So if we just visualise switching places, and focus really, really hard, then-"

Izuku blinked. He let out a shaky laugh, stumbling backwards a few paces and reaching back an arm to steady himself on the bed.

"Okay, that's new," he murmured, voice slightly lower and smoother than before, pressing the heel of his hand to his temple and grinning nervously. "This is definitely something we need to practise, right? I feel bad taking up your body all the time, so this'll be a really good way to share it!"

Another shift. Collapsing into a sprawled sitting position on the mattress.

"I-I don't really mind you being in charge most of the time! It's really nice to feel so confident and know what I'm doing! And you help so many people, how could I be upset about that? A-Anyway, I think, if I really didn't want to do something, I could've stopped you." A shrill, embarrassed giggle, barely muffled by a palm. "B-but you're so bold... How do you get so close to girls without getting flustered? Th-they're so... so pretty! A-and you just hug them and flirt – you flirt with everyone, and it's so... That seems so scary to me!" There was a pause, and a small smile, green eyes gazing downwards. "I hope I'm just like you when I'm older- um, is that a dumb thing to say? I- I mean, you're me, so I will be you, and it seems strange to look up to myself, but this situation is really strange anyway, so does that make it normal? I- I don't know!"

He fell back across the bed, arms flopping out on either side and legs hanging over the edge. His heart was beating fast – with anxiety or excitement, he didn't know – and he couldn't help but release another chuckle.

"It is weird, isn't it?" He remarked, sitting up again and rubbing the back of his head. "We're the same person, but we're also... Not. We've had different experiences, and we approach things differently... I guess it's kind of like you're my younger brother, in a way. Okay-" Izuku hopped to his feet, hurrying over to the chest of drawers to find some socks- "We're clearly not going to be able to go back to sleep like this, are we? How about we go for a jog and see if we can sort all of this out before classes start?"

Hands pressed against the chest of drawers to keep balance. An eager grin, and a scarred hand swiping up a pair of All Might socks to clumsily pull on.

"Th-this is so cool. Weird, but really cool! I have so many questions to ask you... Especially about One for All! It's so awesome to have someone I can share everything with. What was that flashback about? Those were the past holders, right? And that was the first holder who spoke with us?! It was amazing! Oh! I've seen a few of your memories sometimes, does that mean you can see mine? I want to learn everything you know – you fight so well, and you're really good at controlling our Quirk, and you always know exactly what to say – I really want to be able to do all that, too!" A pleading expression, and hands linking in front of a shared heart- "Please, teach me!"

His eyes squeezed shut and he laughed, fond and bright, leaning sideways against the chest of drawers. He had never taken off his gym uniform after training, so he just zipped it up to his chin, already knowing it was chilly outside by the cool breeze coming through his shattered balcony doors.

"I'll share as much as I can," Izuku assured, grabbing his phone and tucking it in his pocket, just in case, then grinned deviously. "Race you outside!"

The leg he raised to take a step stopped unexpectedly, and he let out an undignified yelp as he fell forwards, slamming into the ruined All Might rug. A scarred hand pressed into the ground, raising the torso. Green curls bounced as the head shook in disbelief.

"W-We're the same person! How are we supposed to race?!"

~

Bro, the amount of passive voice at the end there to signify Teen Izuku being in control nearly ended me, but I think it turned out alright?? I'm so excited to write more Izuku and Deku interactions in the next arc, man, I just know it's gonna be really cute 🥺🥺