The Devil Slayer of UA

[ThatOnePsycho]

Izuku sat in the guild hall doing breathing exercises. Mira had just placed a plate of food in front of him, rubbing his back comfortingly, "You'll do just fine; You're a member of Fairy Tail. Nothing UA can throw at you can be harder than the jobs you go on."


"Yeah," Izuku said with a weak smile, taking a sip of orange juice, "it's just jitters. I've waited my whole life for this. If I fail-"



"They're dumbasses," Gray said, half naked, "You're strong, you're smart and you're going to get into UA, buddy."


Izuku finished his breakfast, before stepping into a portal shaped like swirling water and coming out facing UA High. Walking up to the building, Izuku let a hint of confidence fill his heart. He would do this, and then get back to Fairy Tail in time to celebrate with the rest of the guild.



—


Izuku clenched his fists as they got off the bus, silently thankful he was in a different testing ground than Bakugo. Once everyone was out of the bus and milling around, Izuku let the marks of a Devil Slayer roll up his gloved right hand and across his arm, up to his shoulder, where he forcibly stopped it. He didn't need the full Demonization for this.


Immediately as they were told to go, Izuku rushed to the side, expecting most people to focus on the main thoroughfare, and began to try and pick off robots on the side.


"Water Devil's Laughter!" Izuku called as he caught sight of the first robot. At the same time, a second came barreling out of the alleyway and Izuku turned, water spinning rapidly around his fist, "Water Devil's Drill Fist!"


Jumping onto a rooftop easily, Izuku generated a bow of water, drawing back the "string" so it was even with his cheek as an arrow the size of a jousting lance appeared on it. Targeting a small pack of robots, Izuku loosed the arrow, letting it fly straight and true in the blink of an eye, "Water Devil's Boiling Destruction Bow."


The arrow hit the center of the robots, exploding and tearing them to pieces with boiling water. Turning to look at another robot, Izuku created a vortex of water around it, "Water Devil's Swirling Prison and Water Devil's Execution!"

The robot was torn to pieces as the vortex closed in on it. Izuku turned, continuing on his path until a loud buzz filled the air and a giant robot was released into the area. Landing on a building close to it, Izuku jumped up as it swung a fist at him and landed on the arm. Throwing himself higher and higher, Izuku reached the robot's head, breathing in until his lungs protested, he howled out his Rage to the world, the spinning vortex of water drilling through the robot's head.


—


"We made it back alive!" Natsu called as he kicked open the door to the guild, only to blink as he found the Guild in the middle of a party, "What's going on?"


"Today was Izuku's entrance exam, flame brain," Gray snarked.


"Ah, crap, it was? How'd you do?" Natsu asked the younger boy.


"I did pretty well," Izuku said with a smile, "where were you, Natsu?"


"Don't worry about it, now's about you," Natsu said to the boy he saw as a younger brother.


"Entrance Exam?" Lucy asked.


"Izuku's trying to get into a procedues school," Natsu said.


"Prodigious, Natsu," Levy corrected.


"Right, that," Natsu said.


"I don't get why you're all celebrating," Laxus called from the second floor, "he just finished the exam, he didn't get in."


"Lighten up, Laxus!" Gramps said, "Who's the girl behind you, Natsu?"


"I'm Lucy, sir," Lucy said, "I was hoping to join Fairy Tail."


"I see, we can do that after the party is done, for now, grab some drinks, something to eat and join us!"





—

 

[ThatOnePsycho]

Next chapter will be longer, as it deals with the battle trials.

---

Izuku walked through the halls of UA, a spring in his step. He was here, he was at UA, he was a student here now! Izuku was wearing the UA uniform, using the slight allowance for customization to wear a single black glove on his right hand.


Stepping into the classroom, he found a tall, muscular boy berating Bakugo for having his feet up on the desk, to which Bakugo was responding in typical Bakugo fashion. Swearing and explosions.


"Fuck you, Glasses, there's no rule saying I can't do this! Now, pull that stick out of your ass, go sit down, and shut the fuck up!"


Bakugo's eyes landed on Izuku as he crossed the room and he growled out "Deku…"


"Bakugo," Izuku said, calmly, as he sat in the chair behind Bakugo. The ash blonde ground his teeth, before spitting,


"How'd you get here, with your weak ass little portal Quirk?"


"I used magic," Izuku answered truthfully. That just seemed to make Bakugo get angrier.


"Stop with that bullshit magic talk!" Bakugo snapped, lunging for Izuku, only for a voice to cut across the space between them.


"That's enough," a lazy voice said, and they all turned and found a man in a yellow sleeping bag staring at them from exhausted eyes, "Save it for practical heroics, you two."


You two? Izuku hadn't budge an inch to fight Bakugo!


"Now, all of you will find a bag containing a Sport's uniform under your desk, put it on and meet me out in the sport's yard in ten minutes."

—


Shiozaki Ibara stepped out onto the sport's ground with the rest of the class, finding their teacher there. Immediately, he tossed a ball at the green haired boy, who caught it, "Midoriya, what was your record for the ball toss in middle school?"


"I don't know, who knows that off the top of their head?"


"Well," the teacher looked annoyed, tossing a baseball at Midoriya, "Use your Quirk to launch that ball as far as possible, so long as you don't step out of that circle."


Midoriya stepped into the circle, creating a swirling ball of water around the baseball. Then he seemed to stretch the ball out into a bow, plunging his hand into the center, he pulled back the bowstring of water as an arrow formed, "Water Devil's' Destruction Bow."


Ibara gasped, bringing a hand to her mouth. Oh, Lord, a boy who was falling down the path of the devil so young! Perhaps she could save him from the hell that awaited him, pull him back to the light!


Midoriya let the bow loose, sending it flying into the distance as he did.


333.5 Meters! The phone in the teacher's hand went off.


"That looked like fun!" The pink skinned girl with horns squealed. Another touched by the devil?


"Fun?" Their sensei said, "you think this is fun? What about when a building collapses on civilians or a villain threatens them? Will it be fun then?"


"Isn't that for us three years from now to figure out?" Midoriya pointed out.


"What?"


""That's why we're here, to learn, not out on the streets already trying to save people and solve crimes."


Sensei went silent, apparently without an answer for that.


—


Aizawa Shouta stared at the boy who had challenged his statement, wondering what he could do. The boy was, of course, right when Shouta thought about it. They were kids here to learn to use their powers, not fully trained pros talking about how the job would be fun. There was, realistically, no problem with letting them have fun with their Quirks until things got serious, most of them hadn't been able to use their Quirks legally at all yet, but…



Damnit, he just didn't want them to end up like Oboro. He was trying to protect them. Maybe he wasn't going about it the right way, but he meant well.


Finally, he sighed, "you're right. I was too harsh with you, Ashido. This can be fun for now. From now on, we'll be going in class order. Aoyama, please step up to the plate."


Few made throws nearly as impressive as Midoriya's, through he was beaten by Bakugo Katsuki, who sent a smug look Midoriya's way, Yaoyarozu, who fired a cannon she made using her Quirk, and Uraraka, who used her Quirk, Zero Gravity, to send the ball to space.


Over the course of the next tests, Aizawa couldn't help but notice how skilled Midoriya was with his Quirk. In the repeated side steps, he let water flow him from one side to the other easily, ranking up the highest score; in the high jump he made an upsurge of water, flying through the air.


He was only first at one thing, but he was in the top five of everything.

 

[ThatOnePsycho]

Ochako followed after Midoriya as class finished, calling out, "Excuse me?"





Midoriya stopped, turning around to face her, "Can I help you?





"I was wondering if you wanted to hang out. You know, get to know your classmates?"





"I was going to visit some friends…" Midoriya trailed off.





"Can I come along, then?" Ochako asked, undeterred, even if it was a little rude.





"We don't even know each other," Midoriya pointed out, "I'm not saying no, I'm sure my friends would love to meet my classmate, I'm just saying, I'd rather at least know your name."





Ochako blushed hard than normal at that. Yeah, she had jumped the gun there, "Sorry, I'm Uraraka Ochako."





"Midoriya Izuku," he replied, before turning. Twirling his fingers in a tight circle, a hoop of flowing water appeared in front of them, the air within warping and twisting, "You go first, I'll be just behind."





Ochako hopped through it, finding herself no longer at UA bit in what seemed to be a western medieval pub. Midoriya came through the portal a second later before biting the water and swallowing it, "I'm back!"





"Hey, kiddo," a man with a pompadour and a corncob pipe said, "Who's this, you're girlfriend? Moving a bit fast, ain'tcha kid?"





Ochako blushed deeply, while Midoriya just said, "shut up, Wakaba," good naturedly. Like it was all part of the fun, "Uraraka, welcome to Fairy Tail."





—





Izuku watched Uraraka look around the Guildhall in awe, stepping away from where the portal had been. It felt nice showing someone his second home; he hadn't done that since he had shown Mom.





"Where are we?" Uraraka asked.





"Fairy Tail, Magnolia Town, Fiore, Earthland," Izuku gave the full address of their location, "My portal allows me to dimension hop to Earthland, a place where magic is real. Fairy Tail is a guild for Wizards."





"Wizards?" Uraraka said, doubt in her voice, "really?"





"Oui, mademoiselle," Reedus said, before drawing a picture of a chair and making it appear, "That's how Izuku knows how to manipulate water despite his Quirk, he knows both Water and Water Devil Slayer Magic."





"We can show you books on magic, if you want. Fairy Tail has a huge repository," Izuku offered, as the door swung open, revealing Gray, Lucy, Natsu and Happy. Lucy seemed despondent about something, "Lucy, what's wrong?"





"Natsu wouldn't let us take the two million in reward money!" Lucy cried, "I'm almost out of savings and rent's due next week!"





"Why didn't you take the reward, Natsu?" Izuku asked in curiosity.





"Job was to burn the book, we didn't burn the book. We failed the specifics of our contract, so we shouldn't get a reward."





Izuku nodded, "Then yeah, you shouldn't have taken the two million. Keeping to the specifics of the contract is an important part of the Guild Charter."





"I forgot you actually bothered to read that thing," Natsu said, while Gray did what Gray did best.





"Um," Uraraka paused before saying, voice nervous, "Why's that man stripping?"





"Damn It!" Gray swore.





"How much do you owe?" Izuku said, fishing onto his pocket for his second wallet.





"17,000, and I have 15,000-" Lucy blinked as Izuku offered her a wad of cash, "Wha-"





"We can't have you be kicked out of your house," Izuku said casually, "it'd look bad if we let our members live on the street."





—





Izuku sat at his desk, waiting for Foundational Heroics to begin. Suddenly, the door slammed open, and All Might entered head and chest first, arms bracing him on the door, and said in a voice that sounded startlingly like Elfman, "I am here. Coming through the door like a Hero!"





Oh, wow, the Silver Age costume; you didn't see that one much anymore!





"Now, it's time for the important first step," All Might said, pressing a button and causing the wall the slide out revealing numbered briefcases, "Your Hero Outfits! Now get changed, so we can begin the first exercise!"





Izuku took his outfit alongside everyone else, going to the changing room and changing as quickly as possible. The basis of the costume was a simple light blue t-shirt and cargo pants. Over it, he pulled a deep long sleeved sweatshirt that covered his arms and with a hood that could cover his face if he had to resort to Demonization, marked with the Fairy Tail logo. A scarf went around his neck, and finally, a pair of fingerless gloves went on over his hands and he was ready to go.





Stepping outside, he heard Ochako say, "Oh, wow, you look good, Midoriya!" Izuku turned to her, seeing her in a pink and black suit with high heels and a mask over her face.





"You look pretty good yourself," he praised in turn, ignoring the blonde haired boy who was trying to talk to Ochako.





"Alright you newbies," All Might said, pulling up a randomizer screen, "the exercise is simple, the right team will be villains trying to protect a bomb for 15 minutes or defeat the left team, which are the heroes. Now, first off will be-"





Izuku registered his own name and Uraraka's as the villains, while the Heros were one Shiozaki Ibara and-





Shit.





Bakugo Katsuki.





—





Katsuki was tuning out his teammate and her plan to bring Deku to "redemption". He only had one goal, find him, and beat the shit out of him for ruining his plans. He was supposed to be the only one to leave that shitty school for Aldera, he was supposed to be the first in the entrance exam. Instead, he was stuck playing second fiddle to Deku. The moment the buzz came for them to enter Katsuki rushed forwards, leaving Vines behind to find Deku.





He didn't have to wait long, Deku was standing along the hallway to his left. He rolled his arms, water forming around his arm and to his elbows, and he said, "Water Devil's Destruction Fists."





Katsuki launched forwards, a hand swinging for Deku only for him to duck under the blow and punch Katsuki's hand, soaking the glove before retreating back. Katsuki didn't realize the problem until he tried to blast after him… And only one hand went off, slamming him into the wall.





The water from the punch had diluted his sweat. That little-





"Deku!" Katsuki roared, blasting forwards and burning through the vines creeping towards their fight.





"Water Devil's Tidal Wave!" Deku slammed his foot into the ground, cracking it and causing purple water to coat Katsuki and throw him back.





Katsuki rushed forwards, abandoning his Quirk for hand to hand combat. Only to realize Deku had picked up boxing at some point, as he bobbed and weaved between Katsuki's open handed palm thrusts and throwing punches into his side and kidneys.





The vines bound Deku then, and Katsuki aimed a thrust right for Deku's gut, only for a vortex of water to form around him and tear the vines and Katsuki's glove to shreds.





Finally, Katsuki gripped the pin of his gauntlet and, ignoring the voice in his ear, fired it. At the same time, Deku howled out, "Water Devil's Rage!"





It was like a horizontal geyser exploded towards Katsuki, putting out the explosion and slamming into him, smashing him through the vines and the walls and into the building across the street.





The last thing he heard before blacking out was AlL Might disqualifying his team.





—

 

[ThatOnePsycho]

Katsuki stomped back into the observation room, water dripping off him. A robot offered him a towel and he snatched it from the machine to dry himself off.


"Now," All Might said, "can anyone tell me why I ended the match the way I did?"


"Both teams fired off destructive attacks within the confines of the building," a girl with a ponytail said, causing Deku to jerk for some reason, "However, Bakugo launched his attack first, while Midoriya only used his in retaliation and, likely, self defense. You had also specifically ordered Bakugo to stand down, which he ignored."


"Correct," All Might said, nodding, while Katsuki ground his teeth, "Attacks like that should not be used in close confines, where attacks will be funneled forwards and do even more damage."


"But Bakugo trying to take down Midoriya even with the disadvantage was totally manly!" A redhead with his hair spiked up piped up.

"Now, can you tell me who was the MVP of the match?"


"Uraraka," Ponytail said, "she didn't release a destructive attack in close confines, and unlike Shiozaki, she wasn't focused on, from what she said prior to the match, "releasing the sinner from the Devil's spell". She merely guarded the bomb until the match was canceled."


"I was just trying to save him from himself," Ibara said, "is it not the duty of heroes to bring those who have fallen from the righteous path back to i-?"


"That's bullshit!" Katsuki finally exploded, "I only lost because Deku's bullshit water diluted my sweat! He cheated to win!"


"Do you think every match you'll go up against will be advantageous to you, Young Bakugo?" All Might asked, "It's an important part of being a hero to be able to adapt to opponents your Quirk or fighting style is disadvantageous against. Young Midoriya knew his ability to do mid scale water attacks would put him at an advantage over you."


---

Ochako watched Midoriya open a portal at the end of the day, ducking out before Bakugo could confront them. Stepping through, he gestured towards the repository as a orange haired man wearing sunglasses and a fur lined green coat slammed the door open with a look of terror on his face, "We got a problem! Erza's on the way back!"


A grin spread across Izuku's face while Ochako looked confused, "Erza?"


"Fairy Tail's strongest female wizard," Izuku explained. Ochako watched as a redhead in armor entered the building, dragging a giant horn with her. Izuku took off, two steps at a time, and Erza's clothes flashed into an armorless, sleeveless button up shirt and caught the hug Izuku threw himself into, "Erza!"


"Hello, Izuku," Ochako blinked at the voice that sounded almost exactly like Yaomomo, I see you got into UA! Where is the Master?"


"He's out at a Guild Master's meeting in Clover," Mirajane said, "What the horn?"


"It was from a monster I killed on my last job, the villagers were so thankful they decorated it. I intend to move it to my room in Fairy Hills don't worry. But first, Natsu, Gray, Izuku, I need your assistance with something. The elimination of the Dark Guild Eisenwald; rumor has it they're looking for a dark artifact to cause chaos."


Ochako noticed Gray and Natsu immediately butt heads, only to pretend to be dancing together when Erza looked over at them.


"Right," Izuku nodded, turning to Ochako, "If I'm not back by tonight, I keep a permanent portal to my house in my apartment at Fairy Tower, use that to get home. If Erza needs me for this, I'm gonna go. Don't worry about making an excuse for me if I'm not back in time for classes, ok?"


"Ok?" Ochako said.


"Alright," Izuku said to Erza, "I'm ready to go."


—


Kageyama was walking down the corridor of the train, before a hand suddenly launched out at latched onto his wrist. Looking over, he found a teenager staring at him, a red head with a slumped over salmon haired boy next to him, and a dark haired man and blonde on the other side all except the unconscious salmon haired boy, looking at him in curiosity.


"What is it brat. Didn't anyone ever tell you it's-"


"Why do you smell like a demon," the boy said, voice icy.


"What?"


"Why," the boy's grip grew tighter, black markings moving up his arm, "Do you smell like a demon?"


"Hey, bitch!" Kagayama called to the redhead, "control your brat-"


Two things happened at once, Lullaby was jostled from Kageyama's pocket as the brat's grip grew so tight his bones ground against each other, and the boy's eyes landed on the flute, growling, "Lullaby!"


The next thing Kageyama knew, he had been thrown across the train car and the boy had stood up, purple water flowing around his leg. Kageyama lunged forwards, covering Lullaby with his body as the boy slammed his foot down, black covering the right side of his body, "Someone pull the emergency brake and get as far away from here as possible, it isn't safe anywhere nearby!"

 

[ThatOnePsycho]

Izuku gritted his teeth, the repugnant smell of a demon… No, not just any demon, Lullaby, the demon of mass murder music magic, filling the car. Spreading his arms apart, hands thrown wide, he created two waves of water and slammed them into the dark haired man, clenching his fists together and forming the waves into a sphere holding the man, "Water Devil's Prison!"


Let's see him get out of that.


The man fired a spike of his shadow at Izuku, who gritted his teeth and prepared for impalement... Only for an ice wall to appear and catch the spike, "Thanks, Gray!"


"Anytime, buddy!" Gray responded, running across the gap and slapping his hand against the purple water, freezing it solid. Izuku let go of his grip on the water, content that the man, and Lullaby, were frozen solid.


Which was why Izuku was so startled when Erza cried a warning and Izuku turned just in time to dodge a dagger of shadow from the man halfway submerged in shadow. Shit!


Erza brought her sword down in a two handed executioner slice, only for the man to slip into his shadow and out the window. No, he didn't, not on Izuku's watch!


Izuku kicked open the wall of the train, running past the evacuating crowd. He could hide in the shadows, but he couldn't hide Lullaby's scent. He had to kill it before it woke up. Izuku felt the demonization marks spread further than he had ever allowed them to before, covering his entire face, horns starting to grow from his forehead.


The man rose from the shadows, firing lances of them at Izuku, who charged through, uncaring that his UA uniform got torn in the charge. He grabbed the man by the throat before he had time to react, reaching to tear Lullaby from his hip, only for a dark voice to say, "That's enough. I will not die so easily."


And then, the flute began to grow, swallowing the man and forcing Izuku back as it grew into a mountain sized beast, seemingly made of wood, with three pink glowing eyes. It hadn't been dormant, Izuku realized as he allowed the demonization process to swallow him completely.



It had been waiting.





—


Lucy ran up alongside the others, stopping as they found a winged, demonic rabbit like creature flying around the giant monster, releasing huge blasts of purple water at the creature.


"You don't think…" Gray started, only to trail off.


"Demonization? It looks like it," Erza said.


"Demonization?" Lucy asked.


"People who use Devil Slayer magic like Izuku eventually get Demon Genes mixed in with their human ones. By letting those genes take control, they can take the form of a demon. It's a dangerous technique, so Izuku doesn't use it lightly. Come on, we have to help him."


Erza flashed with light, before appearing in a set of armor that looked like what a winged templar would wear. Swords began to appear around her, while Natsu breathed out a torrent of fire and Gray called up to Izuku, "Unison time, buddy!"


Water began to circle around Izuku's overly long arm, turning into a giant drill as he landed on the ground. Gray planted his hand on Izuku's back, the drill freezing over as their magical energy spiked. Erza cried out "Now!" And everyone other than Lucy, who had been watching in awe, launched into motion.


Erza took off into the air holding a sword, the others following in her wake. Dodging a sweep from Lullaby's arm, she drove the sword in her hand into its head, the others peppering its body and all of them leaving small ghostly blue flames rising from them, "None Shall Escape My Grasp, None Shall Escape My Sight! Natsu!"


"With Flames In My Right Hand, And Flames In My Left Hand! Put Them Together And This Is What You Get! FIRE DRAGON'S BRILLIANT FLAME!"


Izuku took off, apparently not slowed an inch by the huge chunk of ice on his arm, and waved the other, washing away the red flames burning away Lullaby's face, only to leave the same ghostly flames burning from it. Lullaby let out a pitiful, especially for a demon, wheezing noise before Izuku drove the drill into the demon's face, "Devil Slayer's Frozen Drill!"


The drill began to spin around his arm, tearing chunks off Lullaby's face, until the water inside grew more forceful than the ice on the outside could take and it shattered in an explosion of ice and water that blew Lullaby's head off completely.


Izuku landed, sharing a side fist bump as the pitch black on his skin receded along with the wings and ear-like spikes of hair. Running a hand through his messy hair, not that it did anything notable to Lucy's eyes. In front of them, Lullaby shrank down to it's original form as a flute and Izuku picked it up, staring down at the three eyes… Before coating his hand in water and crushing it, the remains burning with the ghostly flames until nothing was left, "And now another charm is o'erthrown. Come on, we still need to find out why Esienwald wanted Lullaby."