Heyo everyone and welcome to a new story!

Now today this is about one of my new favorite shows, My Hero Academia. Seriously, this show and manga is in my top 5 easily for how show stopping it is; I read all of the manga in like 1 day and I teared up in the first episode... It got me invested that quickly. Anyway, this story features bits from the manga and starts at the point where the new season of the anime is gonna start so... I dunno, do whatever.

Anyway, so this story is pretty much about my take on Izuku's personal One For All. What do I mean by this? Well, you know how Yagi has those 2 forms right? Buff and skinny? Well, I was thinking... Why doesn't Izuku have this? Sure, All Might explains it like a guy holding in his stomach but it can't really make him grow real tall and buff... right? No, I don't really think it can. So in my head, that means that there must be some sort of side-effect for each wielder and I thought that since Izuku has such great endurance and a tolerance for pain that I might want to play it off that.

So pretty much the premise is that Izuku learns of a side-effect to his version of One For All where if he feels enough pain he will lose all inhibitions and let the pain guide his actions, making him go overboard using things like 150% Power without thinking and stuff like that. Now don't worry, this doesn't make him invincible or anything, it still hurts him and he can feel it but its just a little boost that I thought of that could go along with his character.

As for the pairings... I want this to be a harem cause I usually write these in stories and I really like the BNHA females and all the characters in general really and think that anyone would work with Izuku but I dunno... Let me know if you'd be okay with a harem. If not, then I'd probably go with Urakaka cause you know, she's adorable and awesome or Mina... Blame FanFiciton for this but it has become probably my favorite ship... Dunno how, blame 123PearlShipper. Seriously. But I dunno, I also really, really like Toga for some reason... I dunno. I want it to be a harem but hey.

Anyway, now lets get onto the first chapter of Adrenaline!

Blood.

T-There was just so much of it. So much of it everywhere. It was leaking out of his body like water from a tap, slowly dripping with a repetitive and monotonous irritation that just rang all throughout Izuku's head at a constant pace which only made it even more painful. Alongside this, he could feel the fractures and breaks in his bones, how his fingers were cracked and damaged almost beyond repair as proof of his exertion and his strife, how his lungs were steadily breathing in and out next to his unstable heart.

As The blur around his vision began to wash over to the point where he could vaguely make out shapes and colours, Izuku knew what was going on. He was in Yuuei, at the tournament. A-And he was fighting Todoroki… It was at this point the burning hot flares that had previously been etched quietly into his skin began to claw back at him, becoming another reminder of his fight. In a moment of weakness towards his opponent, in a moment of kindness and compassion for Izuku, he had yelled out with all his might as his bones had rattled around inside him that the Half Cold-Half Hot Quirk owner's abilities were his own and weren't his fathers.

The boy had then proceeded to decimate Izuku's body with his long dormant fire powers. Not the smartest of moves…

Chuckling slightly before recoiling at how it jostled around the bones in his chest, the green haired boy decided to remain in his slumped position near the edge of the arena to regain any semblance of feeling in his body; if Todoroki was strong before, this new fire power was going to set him up leaps and bounds above the rest of Class 1-A… Maybe even the entire year.

And then, like a flood, he remembered that this was being broadcast, that everyone in Tokyo was watching, that his friends were watching, that his mother was watching. He remembered his promise to himself and to everyone that he would get through this, to show them what he was truly like and how powerful he could be; that his dream wasn't a distant figment that could never be achieved. And then he remembered that he had thrown that shot out of the window when he spoke up and told Todorki to use his powers.

Sure, he was happy for his classmate, immensely so; Hell, he could write so much more in his notes about this discovery. However, he couldn't help but feel a nagging want in his soul, in his heart about not being able to show off to his fullest potential.

Oh well… Always next time.

Then it hit him.

Those eyes, he felt them staring into his soul compelling him to move just that little bit more. That cloud of figures that existed in a plain not of this world with eight pairs of eyes that glowed with such intensity and passion that Izuku could feel the drive flow back into him. Those eyes… the eyes of One for All.

Gritting his teeth, Izuku made up his mind. He had given his all, his 100% but to be a hero like All Might you needed to go beyond that, to reach the level of power and attainment that the previous One for All owners had you needed to go beyond your everything. Before his eyes, flashes of the UCG Villain Incident arose and he remembered how hard All Might had fought for them, how he was constantly going above his power to beat Nomu. And now he needed to be more then All Might.

Curling his hand into a fist around the broken earth, he felt his bones mash and grind against each other unevenly but he didn't care at this point. In an almost trance like state, Izuku rose to his feet in a shuddered and shaking mess of human flesh. Soon, sound returned to his ears yet all he could hear were the hushed whispers if the crowd and the sudden stopping of trainers dragging across the dirt. Lifting a shattered visage of his one healed hand to his face, he gritted his teeth once more as attempted to rub the blur out of his eyes only to cover his palm in a thin layer of blood that was welling up from his mouth. Smirking, Izuku's eyes decided to clear.

Before him stood the clearly shocked form of Todoroki Shouto, the son of Endeavour stuck in a phase of stillness that spread over the whole stadium. Twisting his head, the green haired boy caught the eyes of several teachers and students who all looked upon him with inquisitive and impossibly large eyes of worry. Foregoing their attention for his opponents, Izuku cracked the bones in his hands in a painfully loud way that set every nerve in his body on fire but to him all it did was fuel a newly built fire in his core.

"Round 2 Todoroki."

In the stands, the rest of Class 1-A could only look on in shock and disturbed glee as they witnessed the revitalisation of Midoriya. None of them could have predicted this, that Izuku would be so willing and full of strength that he would be able to stand up and continue fighting after being so mercilessly beaten down by Todoroki's new powers and even his own Quirk's drawbacks. It was extraordinary what they were witnessing.

"W-Woah, who knew Midoriya had it in him?" Kirishima spoke up in a shaky voice, the red-haired boy glued to the scene before him just like the rest of the class.

"Y-Yea and all this is coming after he had already smashed his bones to nothingness beforehand… Damn." Jirou couldn't help but agree, the punk girl twirling her earphone jacks around her fingers to seize her ever growing tension.

Some members like Hagakure and Mina were gripping the rail in front of them so tight that I could snap at any minute, worry and concern etched into the pink skinned girl's face while the shuffling of feet and constant creasing of clothing told of the invisible girl's feelings about the situation. Others like Mineta and Kaminari were looking on with glazed over expressions with a mix of jealousy thrown into their concern for good measure while some were unreadable like Shouji and Tokyoyami who were looking at each other with an unknown expression regarding their classmate and people like Iida and Momo were talking quietly about the possibilities of how this happened after Izuku had already taken this much damage.

Some were like Uraraka, with the girl having folded in on herself with sheltered concern that leaked out into the world with her eyes still fully engrossed into the battle. And further still, others were like Bakugou who, while appearing un interested and unconcerned, had their eyes locked onto the scene through the corners of their gaze.

Best to say, everyone was waiting on baited breath to see the outcome of this new factor.

With the teacher, they all watched in morbid curiosity as the crowd shuddered and cringed at the harsh cracking sound of Izukus fist, the bones clashing against each other in a hard snap. Glancing at each other, they all began to quietly mummer about these new factors. Supposedly, the match should have finished a few seconds ago, but Izuku had gotten back up in time to still be in the game

And from this stand, All Might sat with a fierce veil of concern on his face as he looked upon Young Midoriya.

In his mind, Yagi couldn't help but feel responsible for this; it was his Quirk that was making Izuku do this in the first place, make him hurt himself every time he tried to save someone or do any kind of heroic act but also in his mind, he was confused and intrigued by Izuku's new actions. Sure, in his time being a hero he had had some exhilarating fights that had forced him to stand after being brutally beaten down but this… This was something else entirely.

While he was lost in thought, the quiet pitter-patter of footsteps drew the attention of no one as the Principal made his way over to the skinny man's frozen form. Setting his tiny body down next to the man, the Principal spoke in a hushed tone.

"Do you know anything about this Yagi?"

Drawing the No. 1 Hero out of his stupor, the man quickly responded.

"if I'm to be honest… No, no idea. Nothing to this extent has ever happened to me before."

Raising his eyebrows at the taller man, the mouse gave a small sniff.

"What about the fight with Chainsaw? Or the Hateful Eight? They both took you down to your last legs a few times, just like with young Midoriya now… So, what do you mean?"

Glancing down at the field, both men just sat there for a minute as they looked upon the smirking, battered form of Midoriya Izuku. All around his body, a thin veil of red and blue lightning crackled and sparked the air as his skin began to make marks and indentations very lightly on the flesh. And then there were his eyes; his pupils appeared small and almost empty amongst the much larger white layer of his sclera but they were there and they were conducting sparks and strokes of lightning like a generator until his eyes were lost in feeds of blue and red.

"When I was fighting them, I was fighting to save people and to help people… At the minute, Midoriya is finally being selfish, he is deciding to fight for himself and show his power. An almost villainous act in the eyes of some, but there is something else that is there within him… Something I just can't quite place but trust me, it's there."

Taking in a deep breath, Yagi turned to his successor once more.

"And it will make him even stronger then I."

In a dark, drab room in the middle of the city, a lone man sat in a room illuminated only by computer monitors and screens with his body hidden under layers of black and a hood. Idlily, he was messing around with his fingers as he stared upon the forms of 2 boys on his screen, of a battle.

Of the fight between Izuku Midoriya and Shouto Todoroki.

And as he watched, he felt his face break out into an almost impossible grin. This was that boy from before, with the green hair that had threatened to stop his plans at the Training Centre before All Might have showed up… This kid, Midoriya.

"Huh, looks like you got some skill kid. Show me more…"

A few blocks away, the sound of a low TV rumbled through decrepit and blood soaked walls as 2 figures stood before it, bathed in its bright light.

One, was a girl dressed in the outfit of a school-girl with her blonde hair tied in a strange and uneven way that left two strands dangling on either side of her face, of which held a pair of yellow eyes and sharp canine teeth with a bright red blush adorning her cheeks. The outfit was also stained in a fresh layer of blood. At the minute, she was sitting on the cut up body of a man who no longer even looked human as she stared at the 2 people on TV with a lovesick expression on her face, directing her attention at one in particular.

Behind her, stood the form of a tall slender man with mismatched pale skin with wrinkled purple flesh that looked sown together alongside a messy head of black hair and black eyes. For his outfit, it consisted of an open black shirt with a white undershirt alongside black pants and trainers. He was currently staring at his partner with a confused expression.

"Uh, Toga why are we watching this?"

Almost immediately the girl answered.

"~ The green haired one is really cute and cut up… And I think he's going to get more bloody… We need to watch this Dabi, we just need to! I NEED to see this cutie all bloody! ~" Her words were dark and malicious yet in a sing-songy way that made her sound like a child.

Instead of arguing with her, Dabi just sighed and focused his attention on the screen, intend on watching the action unfold.

"Hopefully this'll be worth something."

Taking a step forward, Izuku just let his grin spread as he felt the bones painfully shift in his foot. Before him, Todoroki just sighed before turning to fully face him.

"Midoriya, you're hurt, you can't possibly continue."

To this, Izuku laughed. Then with a narrowed gaze, he channelled One for All into his legs and leapt at the Half-Hot, Half-Cold Quirk user with extreme speed and power, followed by the loud crunch of bone as Izuku shot forward in the air. Rearing his fist back, he just roared in pain as he swung his power imbued limb at the boy before him.

Using his first instinct, Todoroki ducked just before he was hit but that didn't stop Izuku from smashing his fist right into the ice wall to the right of him. In a brutal display of power and pain, Izuku roared out as his fist broke the entire wall in a single blow, sending out shockwaves of power that spread the shards all over the arena. Taking this moment, Todoroki shot backward and away from the green haired boy as he shakenly stood up on his broken legs to examine his fist.

It was clearly broken and badly damaged, with the skin being brunt and scratched around his fingers and knuckles and around that very area blood was beginning to seep out through cracks in the skin, dripping onto the floor like a crimson waterfall. However, Izuku seemed to ignore it, instead opting to pull the digits back into place with his other hand, resulting in a harsh click to echo throughout the stadium. Shaking his head, Izuku's eyes were then back on Todoroki and not a second passed before he leapt at him again, his legs cracking again as he launched forward.

This time, Todoroki had no time to move, instead choosing to summon a wall of ice to at least slow the power infused boy before him down. It didn't. Izuku just smashed through the icy pane like it was nothing, not stopping his assault on Todorki, instead contacting the boy's stomach. With a powerful sweep, Izuku pushed all his power into his fist and skyrocketed Todoroki off into the distance, causing him to cut through the air with unmatched speeds before colliding with another one of his ice sculptures.

Growling at the pain, Izuku just smashed his fist into his chest with a hearty grunt before lifting both of his arms into the air before quickly sweeping them down into an arc. With the speed generated, a massive gust of air like when he flicked his fingers was produced but it was much wilder and crazed as it cut across the skies towards the downed Todoroki. Said boy was just fast enough to catch it, taking off into the air before it caught him. However, the edge got his foot as he was leaving, sending him into a spiral as the earth fell apart around him.

Once again, Izuku was there, his eyes practically gone with the pain as another bout of loud cracking filled the air as he light his arms mid-jump and smashed them down into Todorki's stomach, sending the boy careening quickly down into the smashed earth, breaking it even more. Just as fast, the green haired boy was down at the floor as well, sliding under the bounced form of Todoroki before using his hands like a spring underneath his back to propel a twisting ick straight at the boy's spine.

Howling in pain as he was once again sent into the air, Todoroki tried to combat the ever aggressive Izuku. Throwing his hand to the floor, rows and rows of sharp icicles started to emerge from the floor as he flew, blocking off any path of entrance to his quickly escaping form. Spitting out blood as he watched the dual coloured boy fly off, Izuku quickly jumped back at him, smashing through the icicles with reckless abandon, not even caring when they cut and bit into his flesh. Finally catching up with the other boy, his body trying to stand from being kicked around like a ragdoll, he leapt at him again, foot first.

Rearing it back, he swung at him only narrowly missing his head as he ducked but just like with his arms a blade of air was generate, slicing into the ground behind him. Taking this as his moment to strike back, Todoroki grabbed Izuku's head before lighting his knee on fire and slamming his face into it with a roar, sending him bouncing up slightly before letting the opposite leg which was infused with ice collide with his side which sent the boy spiralling a few metres away.

Izuku wasn't down for long though.

Flipping up backwards with his hands, another snap being generated, Izuku leapt back with his feet raised once more he began to widely swing and swipe them to generate more and more blades to cut towards his foe. Gritting his teeth, Todoroki tried to avoid them but a few nicked his exposed flesh and cut up the ground at his feet, making it hard to stand. Using this opportunity, Izuku ran forward and used Todorki's head as springboard before slamming his body back down to earth like a comet. When he impacted, the world was thrown into disarray once more as pieces of land flew up into the sky and so did Todorki.

Growling, the boy noticed that Izuku was resetting his bones again (groaning as he did so) and so he used this as a chance to end this fight. Preforming a roll, he quickly navigated the floating pieces until he got to Izuku before he slammed a fist of fire straight into his chest, causing a massive explosion of heat and flames to disperse all over the stadium.

"ENOUGH!"

With that shout, he watched as a silhouette of Izuku went flying off into the fiery inferno that had engulfed the whole other half of the stadium. Stumbling back, he took in many deep breaths and he began to feel the effects of Izuku's attacks; a few broken ribs and bruised muscles… Thank God, his ice blocked most of the damage. Bending over, he just let the sounds of the stadium take over.

However, he heard a noise from the fire.

Almost immediately, all eyes were on the fire and with a baited breath they watched as a figure began to emerge from the heat. Out of the flames, walked out an Izuku with gritted teeth and a broken body with blood and sweat dripping down his form. The top part of his outfit had been torn and shredded so much like the right side of Todoroki's outfit he ripped it all off and threw it to the fire. Due to this, his rather built and lean form was exposed to the world and despite the situation many girls found themselves blushing at the display of hard muscle on display on this once scrawny boy; strange and intriguing would be the word that they would describe it as.

Not even taking note of their stares, Izuku just focused all attention on Toodoroki before he started off into a gentle jog.

Todoroki copied.

This then morphed into a sprint from one side to the other.

Todoroki copied again.

This then finally climaxed into an all-out run to the centre of the field for both contestants with battle cries emerging from both of their throats before they leapt into the air and towards each other. However, Izuku didn't have his fist draw; instead, a massive amount of crackling and build up was emerging around… his skull.

Suddenly, everyone realised what he was doing; he was going to infuse his skull with his Quirk and ram it into Todorki.

Roaring, Izuku took off from the ground with lightning speed that Todorki had no time to combat it. Instead, he had to suffer as Izuku collided with him at a slightly lower angle, hitting his chest with his head and causing him to go flying back with shockwaves following his movements as he flew and fluid fell out of his mouth. At the same time, Izuku began to feel the kickback and he too flew back in the opposite direction, hitting the ground sooner and then repeating an action of colliding with the earth before coming to a stop as Todoroki hit the earth as well.

The stadium went quiet as they waited for either of them to move.

They didn't.

And done! So, how was it? I like'd it, I think my fighting is getting better and I really like writing brutal writing so this was enjoyable. Now don't worry, they ain't dead... Maybe. Anyway, next chapter will see the outcome of this and the reactions to Izuku's fighting from the people mentioned in this chapter as well as some parents...

But yea, thanks for reading and I'll see you back here next time for more Adrenaline!

-Jack