Fanfic #176 Unbound by Sky by Quess(RebornXMHA)

This fanfic is a crossover between Katekyou Hitman Reborn and My Hero Academia following Tsuna in the word of MHA. I really like this fic because Of the version of Tsuna we're following in this fic and it explores the Todoroki family pre canon.

Synopsis: Even ten years later Tsuna manages to get pulled into some time travel shenanigans—courtesy of Lady luck giving him the middle finger. Maybe someone should tell Shoichi and Spanner that you shouldn't leave a portal to another world open while guests are in their lab. Featuring the young Todoroki siblings and Tsuna taking care of these kids because goddamn they need a mentally stable adult that won't take shit from a man-child projecting harder than a child beauty pageant mom.

Rated: M

words: 97k

https://archiveofourown.org/works/20142982/chapters/47721085

Here's the first chapter:

When Tsuna was young, despite any objections he might've outright said, he was always forced to go through rather odd, or downright dangerous, situations. Take being a mob boss for example. If ten years ago you had come to his house and said he would lead one of the most influential famiglias in the world, he would've laughed and said you had the wrong person before dialling the police. But if that person happened to be Reborn, well, things were going to go his way no matter what.

Don't want to be Vongola Decimo? Fine then, you'll be Neo Vongola Primo!

Hell, even now with his experience and power, Tsuna wouldn't dare cross Reborn. But if he was going to get shot at anyways for his guardian's rapidly accumulating property damage, might as well tease him about his height. Not that he was much of an exception; he was one of the shortest out of all his guardians.

Where was he going with this?

Oh yes. Tsuna's inability to reject his fate.

To be fair, perhaps this time, it wasn't completely the weapons development unit at fault. More like ninety percent. He really should've listened to Shoichi when he warned him about going into his and Spanner's personal workshops. They were apparently working on the Bovino famiglia's ten-year bazooka and its space-time capabilities (that really should've been the first red flag). But he was looking for Lambo and for some reason, the teen always sought shelter in an extremely dangerous, highly unstable, experimental, and possibly explosive weapons laboratory by the two most impulsive engineers who were each other's impulse control.

The last thing he saw before Lambo accidentally tripped on a bundle of cables, which short-circuited the giant machine— thanks a lot hyper intuition you piece of— was a bright flash of light and Spanner erasing the twenty-five into a zero on a "days since an accident" sign.

When he opened his eyes, Tsuna saw not the duo's laboratory but a country road in Japan. If that was it, he would've congratulated Shoichi and Spanner for creating a transporter that didn't make the user nauseous or lose consciousness. But that situation didn't fit the maelstrom of chaos that fate gave to Tsuna, no, not only did he travel back to his "home" country, but a few people who drove past him were beings who he could loosely call "humans". Some looked normal, some like very intense cosplayers, but others looked very alien with severe mutations—almost as if the Millefiore took their Flame-hybrid experiments and cranked it up to Frankenstein.

And Tsuna… and Tsuna could only mentally sigh at his situation. If he were ten years younger maybe he would've freaked out and panicked. But now?

"Can't believe I got used to being thrown through time and space. Why is this normal for me? How did I get here? Oh yeah, Reborn ," he sighed, twidling with a special ring on his finger.

He fiddled with the metal dials on the ring until he heard a buzz and people screaming through his earpiece.

"The ring's response time was faster by point eight seconds, nice. Hey, Tsuna are you okay?" Shoichi asked.

He dusted his mantel with his other hand, sending a location ping with the transmission ring. "I'm fine."

"Tenth where are you? Are you okay?" his trusty right-hand asked. "On a scale of 1 to 10 how badly can I punish these idiots?"

God, we are all way too used to this.

"I'm not sure, I'm fine, and I'd rather them fix this problem than waste time repenting for actions they'll definitely do again," Tsuna replied calmly as he explained his surroundings. "So either I entered some secret human experimental zone or I've been sent to a parallel universe."

"The latter."

He sighed. "Please say it's a universe we travelled through before."

"Luckily for you Vongola, it is. I think it was about three years ago with Basil." Spanner said before explaining the world he found himself in. "Oh yeah, there should be a Vongola Headquarters in... Musutafu City set up by Basil so go hang there for a while. The Vindice have no authority over there as far as we're concerned so you don't need to handicap yourself in a fight. Got all that?"

"There aren't Dying Will Flames but Quirks and about eighty percent of the world populace has a weird roulette of powers ranging from simple animal mutations to possibly reality-warping laser death cannons. Because of this, Heroes are an actual profession and there are laws forbidding the use of Quirks in public due to safety concerns."

He repeated it as if saying it would make it any less ridiculous.

"Yeah, pretty much. Sorry Vongola, but it might take a few weeks to fix the machine. Maybe a little more if your Storm doesn't revoke our thumb privileges."

Tsuna so badly wanted to scream, "why me?" and "I don't want to do this!" but buried those complaints deep within himself along where all his hopes and dreams of having a normal, peaceful life stayed.

"I'll figure something out. Besides, a few weeks without dealing with the mafia sounds great to me."

Spanner chuckled. "Just remember your little vacation when you come back. I hate fighting with the guys at finance. They already tried to cut our budget in—"

Tsuna hissed at the piercing squeal of the mic screaming directly in his ear. "Are you guys al—?"

He felt a sudden chill down his spine, knowing exactlywho took over the intercom.

"So you think you can just get out of your responsibilities, do you?"

"H—Hello Reborn." Damn it he tried not to stutter. "How are you doing?" Oh, he could just feel the glare through time and space.

"Just fine," he replied in an upbeat sarcastic drawl, "but I wonder how your kneecaps will be in three weeks."

"How is everything my fault?" he mumbled as he observed his surroundings.

"A good boss should be able to avoid such problems." He chuckled deviously before his tone lowered. "Now, shut up and listen. You're a mafia boss, Tsuna. Do you understand? You are not a hero."

Tsuna weakly covered his smile with his hand. Despite what Reborn said, he could hear the underlying worry and trust in his voice. It reminded him of his youth when the weight of everyone's lives clutched his shoulders; when he feared the tears of his loved ones would drown him. When things turned complex and he thought he hadto be a hero to save others—noble and righteous. Someone he wasn't.

But he was only human. He didn't need intricate goals and motivations, he only needed to see what was around him. Some may call him selfish but even the sky had its limits. When one took in too many elements without gaining anything in return, even the sky would break. Any more and he'll crack, as fragile as glass, pieces shattering, the rifts webbing what was left. Coddling him would only sand down the edges but the gaping wound will still be there, hollow and empty.

But Reborn? He was none of that. He didn't take shit from anyone and that included his student's detrimental selflessness. He was the one to shoot at the hole in the sky, tell you to take a hard look at yourself, and then collect the pieces you thought you lost to help you rebuild yourself. It was incredibly tough but he didn't do it out of selfishness but because he knew he could do better.

"I'm not going to jump in at first sign of danger," he said light-heartedly, "I'd like to remind you that I'm the most pacifistic one out of all of us."

He clicked his tongue. "That's not what I'm talking about and you know it."

He did. In the past, Tsuna was a coward, a person who ran away at the first sign of trouble. But now with everything he went through, he couldn't help but become more assertive and to face the danger with pride; he couldn't help but aid people who were in front of him. Not from heroism, but because he could. Not that he would rush into a fight, he wasn't suicidal, Ryohei, or some hero.

"It's so nice to hear you care about me, Reborn," Tsuna teased, "but I'm doing amazing right now. I got fresh air, vitamin D, a change of scenery and I finally got to stretch my legs and I feel great! "

He heard Reborn sigh through his headset, picking up on some chuckling in the background that sounded suspiciously like Takeshi.

Picking up his tone, he said in a sinister tone lacing his voice, "Well then, if you have so much energy—" Why did he think teasing him would be a good idea? "—I expect you to spread the Vongola name, recruit at least one hundred people into our ranks, and when you come back..."

Tsuna coughed, briefly weighing his options to either apologize or starting a new life here.

"A—Are you seriously giving me homework ?"

"It's summer vacation for students in Japan right now, isn't it? You should be used to this. Or did you suddenly regress back into your pathetic middle school self?"

"Sadist. You are nothing but a sadist."

"Apparently not enough of one if you have the gall to talk about to me." Tsuna imagined Reborn smugly twiddling the curly cord on a nineteen-seventies rotary phone as he said this. "Maybe I'll talk to Byakuran and have him send me there."

The probability of that was less than point one percent but if being with Reborn for over ten years had taught him anything it was that when Reborn wants something, he'll get it.

Tsuna turned the dial on the ring by a centimetre, slowly making his way back into its original position.

"Oh… Oh no … you're breaking up..."

"Tsuna, don't you dare—"

"Sorry, bye!" He quickly turned the dial, breaking the connection. He impressed himself on how stupidly brave and suicidal his actions had become.

"He'll kill me for sure that but that's future me's problem," he reassured his current self.

With that Tsuna travelled along the road to the nearest town, trying to run from his problem like any responsible adult. Of course, that wasn't necessary when trouble stuck to him like a leech—

"Villian!"

"Please help!"

"The building's crumbling!"

"Children! My children are in there!"

—and he ran towards the screaming without hesitation.

Somewhere else, a young boy clutched onto his mother, the latter of whom was robotically patting his hair, all sense of warmth and comfort that once there lost to time.

"Mom?" he said, voice wavering.

She hummed noncommittally.

"I heard him saying that he might replace you." His little fingers squeezed her harder as if just the thought could make her disappear. "On the phone. He was talking to someone."

Although it happened hours ago, he could still hear the cold, authoritative voice of his father controlling him, his life. It was after their training, or "father-son bonding time" as he heard one of his father's associates called it. He was walking over to where his mom was, nursing an injury, holding back his tears. Tears didn't help anyone, certainly not himself or his mom.

It was only by chance that he overheard his conversation. Usually, if his father wasn't training him, he isolated himself in this office or had work far away from the house. But today it seemed he was unlucky enough to see him outside of his mandatory training lessons.

"—the boy needs more than what she could offer him," he said rubbing his temples, "go search for someone with high proficiency in ice Quirks then refer them to me. I can't have him tainted and spoiled by some amateur."

As an eight-year-old boy, his mind couldn't connect what he was hearing. He knew that his father was looking for someone to train his right side, his mom's side. The side that eased the pain. But then what about his mom? What would happen to his mom? Would she stop nurturing his left side?

He knew his father was utilitarian, selfish. He immediately discarded anything that was a hindrance and cut ties with anyone that would drag him down. Blood included. He already knew that his family wasn't like what he saw on TV. A happy mom and dad who loved each other, siblings who would pull pranks and laugh about it. Even the simplest things fascinated him: eating homecooked meals together during "family time", play multiplayer games and acting silly, and sleep together under one roof. He was envious of those fictional characters. Even those crafted stories had better chemistry than his family. While they had "family reunions" and reminisced about the moments they shared, he could barely remember the face of his eldest brother.

So would this mean that he would get someone like his father to train his left side as well? Did that mean his left side would be moulded into something that causes pain like his right? Did that mean he would be forced to spend even less time with his mom?

"But that's not going to happen, right?"

He looked at her, not understanding the pain and suffering behind those eyes. He hoped that she would call his name with her comforting voice like back then. For her to embrace him, kiss his cheeks and say that she'll protect him. To say that everything would be alright. He knew it wasn't true but it made him feel better.

"You won't leave me alone, right? Mom?"

She hummed once more.