A nauseating cacophony cleaves through her tympanum, shredding the eardrum. It's a sensory phenomena of chaotic sound that pierces her ears. The visceral noise is so jarring that it continues to ring in her ears even after they've been ruptured. She'll never forget the obstreperous fortissimo for as long as she lives. She'll always remember the wet warmth of a liquid touch when she tries cupping her ears in a futile attempt to muffle the pandemonium. She will forever see the crimson color of blood on her hands after holding them out in front of her to see why they had become so damp. The poor girl shall know better than anyone else what hell's gates sound like when they screech open for the devil to come out and play.

Born with a quirk that grants her organic ear jacks, Kyoka Jirou earned her placement as one of U.A's entrance examinees. The hero school candidate had rushed into the physical portion of the test filled with vim vigor. There had been a level of confidence only defined as young nativity. She was all ears when listening to the rules, so she had expected taking out mechanical faux villains to be a cakewalk. It wasn't so easy. Suddenly, the earth shattered, fracturing her valor at the same time. Plates began to shift. Whatever didn't break apart had bent so that a colossal robot constructed to ward off testers could rise out of the ground. Applicants fled immediately. Kyoka was about to join them. But then she saw the brunette girl pinned under rubble from where the monstrous mechanism had excavated itself. The rumbling robot was about to roll over the collapsed contender with its treaded chain track. Kyoka closed her eyes, instinctively turning her head to look away so as not to witness the inbound gruesome accident.

And then… And then she heard it.

The abrasive roar of a chainsaw that came before the scything rip of chattering steel.

A grating rip of metal sheeting reverberated as the sharp piercing sound also stabbed into the gigantic golem. A shrill shriek of steel rang out as it was torn apart in a tumultuous frenzy. And even now, the cataclysmic caterwauling continues. There's no escape from the rampaging raucous that decimates the droid. The behemoth buckles as it's torn apart at the base, metallic fibers creaking and wires sparking with popping embers from where the steel shielding gets mauled. Screeching comes from the machine as though it's wailing in torment. Never had Kyoka in her entire life heard something so awful.

Never had she seen something so awful either.

When she opens her eyes… she sees it.

Elongated saw blades slicked black with oil protrude from what looks like something straight out of hell, metal teeth tipped a dark shade of red. It takes Kyoka a moment to realize the blood came from the source of the chainsaw bars and not from the robot. Dried and crusted scarlet specks dot the bare chest of a boy's fit physique, a ripcord made of copper swaying from his sternum. The grotesque figure has a green motor for a head, engine parted at the mouth where fangs are bared; indicator lights glow a bright yellow hue, eyes fueled just as much as the chainsaw attached to the base of his head. Arms split down the middle allow for additional chainsaw bars that are being swung haphazardly at the automaton that he downed.

Parts get thrashed around, the robot's innards coming loose from the consistent strident strikes of the saw blades. Steel squeals as the chainsaw's teeth grate against it, carving in downwards and then upwards. The malformed boy relentlessly hacks at the opposing metal, harsh noises and shrill sounds sending shockwaves through the beaten bot. Weakened whines escape the machine as it's chopped to its core. When the slasher severs anything remaining between him and the faux villain's power source, he skewers the apparatus heart. The chainsaws protruding from each of his arms stay embedded as he raises the core reactor out from its circuitry. In one fluid motion that serves as a fatal finishing move, he hoists the robot's key component over his head and begins dragging the chainsaw attached there downwards through the hardwiring.

Despite how excruciating the devastating din was to her heightened sense of hearing and how hysterically horrified she was to watch the vicious slaying of the massive machine, Kyoka has to admit that it was a pretty fucking hardcore takedown. No matter the terrifying chainsaw visage and the savagery of the droid's disfigurement, the malformed boy had rescued the brunette girl that would have otherwise been crushed. Kyoka can't help but admire the heavy metal approach. She finds herself studying the stranger's appearance, blown away by how gnarly the destructive blades are. When her eyes roam to the boy's bare chest, a blush the same shade as the blood there begins to fade in. Kyoka's onyx eyes widen and the heat in her face subsides. She realizes there's blood. A lot more than before. Last time she checked, machines don't contain DNA in them. Which can only mean…

A feverish feeling of queasiness overwhelms the girl, nearly making her double over with the urge to vomit. The major spillage of blood came from the boy, the severed parts of his arms and exposure of his head ripping flesh and skin tissue for the chainsaws to function. In order for the cutting mechanisms to operate, they constantly shred his own muscle fibers. The blood leakage is an extreme side effect of the liquid's utilization as fuel. It's no wonder that the boy's pigmentation has become pallid. He's lost a major amount of the vital body fluid. Kyoka studies him closer, seeing now that his body is trembling. Noticing the way that the fatigued figure wobbles on his shaky legs, Kyoka turns to call out for help.

Her ear jacks sway with the pivotal motion of her head. It's hard to judge how loud she's shouting with her hearing still wounded, "Hey! Somebody–"

But she doesn't need to worry about anyone not coming to her call since someone has already arrived, onyx eyes landing on a short statured woman wearing a white coat that billows in the wind like a cape. If not made evident by the large syringe that the lady is using as a cane or the regular sized needle poking out of a netted bun like a hairpin, Kyoka is confident that the senior is the school's nurse judging by the way that she hands vitamin gummies to examinees. Relief settles through the girl's system when she sees her elder getting nearer. Her violet hair swishes with her ear jacks as she turns her head back towards the boy.

Much to her awe, the demonic face is gone and the chainsaws have retracted. She figures a transformation must have taken place while she was looking away. In place of motorized metal is an unruly mess of green curls. Instead of yellow lights, there's an emerald glow to the boy's eyes. An otherwise plain face holds two sets of freckles that make up a diamond formation on each cheek. At first glance, the basic facial features would have her giving no second thought to the fellow teenager. However, she's been giving him more than a simple surreptitious peek; the girl may as well be ogling him, captivated by the shift in appearance from predatory ferocity to docile innocence. Staring at him for as long as she has, she has to admit that she finds him kinda cute actually.

A blush dusts Kyoka's cheeks, applying more pink than her makeup. The girl's stare isn't just drawn to the shirtless boy's face, but also his well defined muscles. Her onyx eyes are bound to pop out of their sockets at the rate that they've been broadening. She realizes as the school nurse walks past her…

"Oh, no! He's hot!", Kyoka only registers that she voiced her thoughts aloud when the nurse casts her a sidelong sly smile. The girl's ear jacks tangle themselves as she becomes flustered, worried that she may have also been heard by the boy himself.

However, that doesn't seem to be a problem… Considering he's fallen flat on his face, having passed out from blood loss and rendering himself unconscious. Kyoka winces, hoping he didn't land too hard and bruise his face.

U.A's nurse tuts with each disapproving shake of her head. The elder woman prods the boy's body with her specialized cane, taking in his sorry state and formulating a diagnosis based on the mess. "Another reckless kid with too much spunk", she sighs before crouching down to his level, "Looks like I've found this year's Toshinori" Kyoka silently wonders which hero with that name could the experienced elder be referring to.

The medical practitioner rolls the bloody body over before she plants a kiss on the unconscious boy's forehead. Through lip contact, the elder woman's quirk is able to heal people's injuries and illnesses. Kyoka catches on upon witnessing the ability in action. The lady was able to land her role as U.A's nurse by being a heroine of her own. Kyoka finally recognizes the woman as Recovery Girl.

But Recovery Girl is still much too occupied with tending to the boy who overexerted himself to notice Kyoka's starstruck stare. The old heroine uses her cane as a crutch to stand back up while med bots lift her patient up onto a gurney. She watches with censorious care as the boy stirs in his state of unconsciousness, "What is it that man is always calling them?" But upon closer examination, her gaze turns tender, "Problem Child."

Sharing Recovery Girl's line of sight, Kyoka can't help but agree with the woman. This boy is going to cause a lot of problems.

AUTHOR'S NOTE

And so begins another story!

As you likely already figured out, this fanfic is essentially 'What if Izuku Midoriya had Denji's transformative ability from Chainsaw Man?'
I won't really be blending much else from Chainsaw Man into this one aside from Pochita (because Pochita is actually the BEST), so Izuku will be the only devil/fiend and you shouldn't expect any characters crossing over, just a fair heads up.

For those of you who are new here, I humbly suggest reading my other works where I blend Tokyo Ghoul and Batman mythos with My Hero Academia. If anyone is coming from Glassy Sky or Legend Of The Bat & Riddle Of The Bat, then THANK YOU SO MUCH for giving yet another one of my stories a chance!

Lastly, I just want to encourage you all to comment your thoughts, since reading your feedback really helps motivate me and I love taking any theories of yours into consideration whether it means making those dreams come true or crushing them!

Until next time!