Disclaimer: I don't own My Hero Academia, or any of it's characters. I use a lot of dialogue and scenes from the anime in this story, with my OC added as a character. I left out a lot of important parts of this amazing anime, so for full enjoyment in reading this, watch the anime before-hand or while you're reading. This is my first (posted) fanfiction, so criticism is very much welcome. That's all, hope you enjoy! :)

Midoriya ran to class, barely making it on time.

"Morning Deku!" Uraraka greeted Midoriya at the door.

"Hello Midoriya." Iida stood behind Uraraka, pushing his glasses up the bridge of his nose.

"Morning Uraraka, morning Iida." Midoriya greeted his classmates. They all got in their seats, waiting for Mr. Aizawa to show up.

Aizawa walked in and stood at the podium. "Today, this class is receiving a transfer student from Ireland." A tall teenage girl walked in. She was roughly 175 cm, taller than Yaoyorozu but a bit shorter than Todoroki. The irish student's skin was very pale, contrasting with her wavy raven locks. The only pop of colour were her green eyes that had the same colour as green jade. They seemed to glint as they surveyed the room, but not in a malicious or cold way. They seemed curious, maybe a bit wary at first.

"This is Ember Kyoso." Mr. Aizawa turned to Ember. "You can sit at the desk in the back." He turned back to the students. "She was transferred to U.A. from her old school because of an incident that presented her... untapped potential in heroism. We usually don't accept anyone after the school year has started, but Ember is a special case. She will go through quirk assessment this afternoon. Come if you want to, I don't really care." Ember sat down at a spare desk in the back, next to Todoroki. They glanced at each other in recognition. Todoroki's lips tugged up in a small smile, something he never did. They definitely knew each other. Class went by relatively quickly and normally that day. Until Hero class…

Everyone exited the changing rooms. Conversations had been at a minimum, with Mineta muttering and drooling talking about what Ember's costume might look like. Disgusting. The thought of costumes had been on Midoriya's mind, not in the same way as Mineta. (Mama Inko taught her son to respect women, unlike grape toddler over there) Because no one knew what Ember's quirk was, maybe her costume could give some insight. The students walked out onto the blacktop. Midoriya surveyed the crowd for Uraraka, who was taking to the new girl, Ember. Everyone else was dressed in their hero outfits, but Ember had on PE clothes. Honestly, Midoriya wasn't surprised. Costumes take awhile to make, so obviously it wouldn't arrive on such short notice unless Ember had submitted a form before. There were 2 parts that weren't standard: first of all, her shoes. They were black combat boots with shiny silver laces. The boots were worn with wear, maybe from her old school. Secondly, a silver belt cinched her waist. It struck Midoriya as a slightly odd fashion choice, but it didn't look bad. At the start of class, All Might explained they would train for the rescue course that monday.

"Sounds like a good opportunity to crush you, Deku!" Bakugo yelled. A couple students behind him rolled their eyes.

Jiro muttered "It's rescue training, not a battle." causing Bakugo to get even more worked up, yelling at her.

"Quiet down! For the next two days, we will have sparing practice. Partner up with anyone you like. Quirk usage is allowed, but don't maim anyone too badly, and killing is, as always, strictly forbidden. I will step in if it gets too intense." All Might warned, looking directly at Bakugo, who just rolled his eyes and muttered something along the lines of 'try me, old man.' All Might pointedly ignored him.

"Now partner up and start sparring!" everyone grabbed a partner. Bakugo went with Kirishima, but glared daggers at Midoriya. Midoriya partnered up with Uraraka and Iida, since with Ember there was an uneven number of students. Others partnered up quickly too, picking mostly classmates they knew well enough to know their weaknesses. Midoriya saw Ember and Todoroki head to a spot in the back to spar in peace. Most of the closer spots were taken, so Deku and co went to spar about 20 feet away from the two. The mock battles started, nothing being too intense except for the explosions in the background from Bakugo bakugoing at Kirishima. Midoriya jumped and punched loosely. This was mostly just to work on analysing patterns and improve precision on moves, so nothing too serious.

Midoriya, Uraraka, and Iida talked for a bit, until they heard something that sounded like rocks being smashed to pieces. It wasn't coming from Bakugo, he was too far away. The sound of ice crystals forming gave it away; Todoroki and Ember's spar was getting intense. Other groups turned to watch, including Uraraka, Iida, and even Bakugo. Todoroki was hurling ice, and Ember was almost a blur, jumping and dodging to avoid the crystals. She anticipated the blasts, managing to get in close enough to strike. She succeeded in landing some hits on his stomach, ankles, and back of the knees. 'Weak spots', Midoriya realized. 'But still keeping it to a minimum by avoiding the neck and head. She must be close with him, no one else with this much skill and strength would miss those.' She aimed with precision and speed, never staying around for longer than necessary. 'So that she's not frozen by Todoroki's ice quirk!' No wonder they transferred her here, she's really experienced and powerful! Midoriya went into hero analysis mode, analyzing patterns and such. Ember's fighting style, a pretty unique form, primarily using gymnastics and lightning-fast reflexes to attack, and quick jumps and clever use of blind spots to defend.

"Wow, she can really hold her own in a fight!" Uraraka commented.

"No kidding." the green-haired teen was in awe of her skill. "Wonder what her quirk is."

"Obviously, speed!" Uraraka said, making Iida turn.

"No, it would most likely be enhanced intelligence. Her strategy is flawless, physical speed and strength like that can be achieved without a quirk." Iida argued.

"No human without a speed quirk could be that fast!" Uraraka argued back.

"Hey guys…" Midoriya's voice failed him. The fight was getting really intense now. Todoroki hurled large chunks of ice at Ember, who used them as stepping stones to get to him. She came in close, knocking Todoroki's feet out from under him. Ember put her hand on his throat, right by his jugular.

But the ice wielder still had a few tricks up his sleeve. He grasped her arm, sending ice shooting up it. She let go, jumping back. Another wave of ice was sent at her, and it managed to hit her foot. From there, it snaked up Ember's leg and to her torso, freezing the girl up to her neck. She was suspended there, kind of like a sculpture you'd see in a museum. Except sculptures tend to talk less.

"You've gotten better Todoroki, I'll give you that." Ember remarked, green eyes glinting in a dangerous but playfully impressed manner.

"You too, Ember. Still not using your quirk?" Todoroki responded, in a slightly amused tone. Midoriya was shocked. The transfer student almost defeated Todoroki? Without using her quirk?! Who was this girl?

"You know me. I don't see you using your flames either, so you can't criticize me. Now, can you get me out of here? Its freezing." Todoroki nodded, and melted the ice. She shook, ice shards dropping from her dark curly mane.

"That's enough for today! Class dismissed." if All Might was impressed by the spar between Todoroki and Ember, he didn't show it. Everyone else, except Bakugo, was shaking in their shoes. It had been pretty scary. I mean, Todoroki was already scary when he was doing simpler things, like freezing entire buildings. But this was on a whole other level. Midoriya couldn't even imagine how much destruction the 2 of them would wreak as a team.

The rest of the day went normally, with Ember being silent. No one dared to speak to her, she was just that scary. When it was time to walk home, Midoriya saw Ember walking to the field with Todoroki. A bright smile graced her sharp features, and even Todoroki grinned slightly. They seemed so natural together, Midoriya could see why they both gave it their all in the spar. They definitely had a strong friendship that Midoriya could only dream of. The two of them walked off, leaving Midoriya to wait for Iida and Uraraka.

"That new girl, Ember Kyoso? She's scary!" Uraraka said as she bounced down the sidewalk.

"I know, I've never seen someone almost overpower Todoroki. In a real battle, he would've been dead." Midoriya responded.

"What really intrigues me is what quirk she has. After the battle, Todoroki said she was not using her quirk. If she wasn't she must have had a reason." Iida said, deep in thought.

"Maybe it drains her, and she can't use it too often." Midoriya postulated.

"Kind of like your power." Uraraka said, which flustered Midoriya a bit.

"Anyway, there's no use theorizing. All will be revealed when her quirk assessment results are stacked on the board." Iida said.

"The quirk assessment! I forgot she's doing that now!" Midoriya said.

"I want to see that. If I run I might be able to get there in time." Uraraka turned back to the school. "Are you coming, Iida?"

"I wish I could, but I have to be at home, family business." the class rep admitted.

"How about you, Deku?"

"I wish I could, but I have a ton of homework to catch up on. Tell me about it tomorrow." Midoriya waved his friend goodbye.

Uraraka nodded, and ran off to the school. Iida and Midoriya walked home. Iida theorized what Ember's powers were, but didn't come up with any concrete ideas.

"Bye, Iida!" Midoriya walked into his apartment complex. He still couldn't shake the feeling that Ember's quirk was really powerful. He'd find out tomorrow, right?"

-Next Day-

"She- what?" Midoriya asked Uraraka.

"She didn't use her quirk!" Uraraka confirmed his thoughts.

"Is that even allowed?"

"Didn't you not use your powers until the throwing test?"

"Well yeah, but I still used them at some point. How high did she score?"

"I didn't see, but the scoreboard will be updated today, heard Mr. Aizawa say so after the assessment. Should already, but we have no way of checking before Mr. Aizawa arrives." the door opened, and 2 figures walked in. Todoroki and Ember, talking about who-knows-what.

"Hey Todoroki." Midoriya greeted the ice wielder.

"Morning Midoriya. Ember, this is Izuku Midoriya." Todoroki introduced the 2. He seemed more open and happier than usual. Usually, Todoroki shrugged off Midoriya, but this time he seemed a bit more relaxed in the green-haired teen's presence than usual.

"You're the transfer student from Ireland, right?"

"Yeah. Ember Kyoso, nice to meet you." they shook hands. She spoke in a thick irish brogue, but despite that, perfect Japanese. Mr. Aizawa walked in, looking grim and tired as usual.

"Okay, class. Because Ms. Kyoso took the quirk assessment yesterday, there's been a shift in the leaderboard." Mr. Aizawa put the scores up. Confusion around the room. Ember had placed second, barely behind Bakugo. This put the boy on edge. Bakugo exclaimed angrily, turning to Ember.

"You see here, new kid, you aren't better than me! I'm still the best here!" She just rolled her eyes. That made Bakugo really angry, and he exploded (not literally, that would've been messy), yelling about how he was so much better and she'd be roasted (literally) later.

"QUIET. You can jabber about this all you want outside of class." the lesson went okay, with Bakugo only exploding (again, only figuratively) twice throughout the lesson. Hero class proved to be interesting again, with 2-on-2 sparring. Partners from the day before formed a team to spar against others. All Might chose who would go against each other based on how they'd performed on Thursday. Unsurprisingly, Bakugo and Kirishima were pitted against Ember and Todoroki.

"I'M GONNA DESTROY YOU!" Bakugo started yelling. The spars started, though almost everyone was watching The Todoroki-Ember-Bakugo-Kirishima match instead of properly fighting. It did start off strong. Bakugo hurled explosions right at Ember, but Todoroki blocked him with an ice wall.

"Thanks!" Ember attacked, using the bumpy terrain from Todoroki's ice and Bakugo's floor-shattering blasts to launch herself at the opposing team. She was deadly effective, surprising the 2. Bakugo got a punch to the face while Kirishima was hit in the back of the knees. Despite being made of rock, he still crumpled. Todoroki's ice shot up the red haired boy's body, encasing him. Safe to say Kirishima was out. Bakugo didn't seem to notice or care. Probably the first one, considering how preoccupied he was with not getting pummeled too badly by Ember. Bakugo tried to hit the lithe girl, but she was just too fast. Ember jumped, flipped, and rolled around him, moving incredible speed and agility. A few explosions hit their mark. There were burns on her legs, arms, and one on her side, exposing blackened skin on her ribs. She was a bit out of breath, panting and coughing.

'Some of the smoke must've gotten in her lungs. Kacchan's blasts can do that to you if you stay too close for too long.' Midoriya remembered when Bakugo first got his quirk and was trying it out, he accidentally smoked up the kindergarten so bad everyone had to be sent home.

Bakugo finally managed to do something other than get beat up. Hr managed to grab Ember's hair, which she'd forgotten to tie back. He yanked, pulling the girl towards him. Bakugo set off an explosion aimed for Ember's face, but the girl managed to dodge, the blast hitting her neck instead. Ember yelped, obviously in pain. She kicked Bakugo's face before scrambling back and crouching down for another attack.

"Are you okay?" Todoroki yelled, sounding genuinely concerned.

"Yeah, just surprised me a bit. Ready?" Ember jumped to avoid an explosion. She attacked head on, this time not being careful about getting burned. Meanwhile, ice sneaked up behind Bakugo. Because he was so preoccupied with Ember, he didn't seem to notice until it grabbed his foot.

"Hey-" the ice encased the boy in less than a second. "Hey!"

Ember walked over to Todoroki, a pained expression on her face. Bakugo blasted himself out, seething with anger.

"Listen here, you little b-" he was cut off by All Might. If the number one hero hadn't ended training, Bakugo probably would have committed his first murder right then and there.

"That will be all for today! Remember, next week we are doing a rescue course!" everyone dispersed. Bakugo headed in, yelling at everyone.

"Hey, wait up!" Midoriya caught Ember while walking to her next class. He sidled up next to her. "You were really good against Kacchan. I don't think I've ever seen him so mad."

"Thanks." Ember said nonchalantly.

"I was wondering- did you use your quirk to beat him?"

She thought on it for a second before answering. "Yes and no. My quirk has the side effect enhanced agility, but I didn't use my quirk itself."

"What is your quirk anyway? Everyone is wondering."

"Doesn't matter. I'm not using it anyway."

"Oh… okay." Midoriya didn't understand. Why wouldn't someone use their quirk? All he'd wanted as a child was a quirk, so why would someone not use theirs?

"Anyway, class is starting." she ran off, frizzy hair whipping around. To Midoriya, she seemed even scarier now. Beating Kaachan without her quirk? He would explode (maybe literally) if he found out. Anyway, Midoriya had the school trip to the USJ to look forward to. Hopefully that would be nice.