Chapter Text
“Ah, Midoriya, right on time.”
“...I’m fourteen minutes late, Principal Nedzu.”
“And because I knew Eraserhead wanted your assistance selecting today’s sparring matches, I expected you to be approximately that late. Come on in, have a seat.”
Izuku did, closing the door behind him.
“I won’t be keeping you long today, so I’m afraid continuing our game of Illinois chess will have to wait. A shame, I was curious to see why you had risked engaging both the Lich Knight and Goblin Bishop simultaneously… ah, I’ll find out next time. I have a new assignment for you.”
“Will this one require me to break any laws? Detective Tsukauchi wasn’t happy about being woken up at three in the morning last time.”
“No. Probably not. Though I suppose that’s really up to you, isn’t it?”
Despite himself, Izuku matched Nedzu’s sly smile.
He hadn’t understood, at first, why Nedzu thought he shouldn’t participate in standard sparring matches with his classmates. True, he had to preserve what was left of One For All, but he wasn’t a bad fighter without it. He’d even been excited about getting better over the course of his second and third years, becoming something akin to the quirkless hero he’d once dreamed of being.
Figuring out why Nedzu deemed these individual lessons a better use of his time had been his second assignment. Izuku arriving at the answer had been followed by the offer of a future teaching position, alongside the passing comment that if Nedzu had been made aware of his analysis skills two years ago he would have personally ensured Izuku made it into UA. Quirk or no quirk.
Izuku was still recovering from that bombshell. He suspected that his hair would be finally done growing back by the time it processed.
Nedzu’s first assignment had been an interview, but Nedzu wasn’t the one asking the questions. Instead, Izuku was instructed to find out, once and for all, what sort of animal Nedzu was.
In what would prove to be fairly standard for his new tutor’s assignments, Izuku’s real task was not to find the answer but to understand that there was no answer. And more importantly, why there was no answer. Nedzu was an animal, and his quirk was derived from the concept of hyper-intelligent animals. He was an animal in the same way Tsuyu was a frog.
And wasn’t that just so cool? Quirks were the best. He’d lost so many more than almost anyone else would ever get, but he would never get tired of thinking about them.
“I’ll try not to get caught, at least,” he responded, to Nedzu’s approving nod.
“Very good. Now, this assignment will be a bit different. Think of it more as a project, for you to work on alongside your other tasks. You have a month. What I want you to do is: write up a shorthand UQET analysis on your classmate Ochako Uraraka.”
Izuku waited for Nedzu to continue.
And kept waiting.
And waited even longer, as Nedzu kept smiling pleasantly.
Izuku felt very much like he was walking into a trap. “And then…?”
“I have given you the instructions.”
Nedzu didn’t have any tea on hand, but Izuku had the distinct impression of him nonchalantly sipping it anyway.
Right. So, Nedzu had given him a month to do something he could do in two minutes. While concussed. And asleep. He’d been doing Unified Quirk Extrapolation Theory analyses practically since he could write, even if he’d only learned the formal term for them last year. And a shorthand one? He was fairly certain he could recite it out loud right here, if he miraculously managed not to get distracted by a mental tangent. Nedzu knew all of that perfectly well.
Games were being played, and Izuku wasn’t sure if he was an opposing player or one of Nedzu’s pieces.
Yup, same shenanigans as usual. Just another day of being reminded that humanity was lucky that Nedzu hadn’t held a grudge. More of a grudge, that is.
“Do I get a hint?”
Nedzu hummed, as if he hadn’t definitely already decided what information he would and wouldn’t give Izuku. “You'll be done when you need to ask a favor of me. One I shall be willing and able to grant, provided you ask no follow-up questions."
“...Right.” That wasn’t ominous at all.
“That is all for today, Midoriya. I believe your class has a non-quirk training session tomorrow, so I will next see you the day after that. And so will the Lich Knight and Goblin Bishop. Though if you don’t do well on the initiative roll, I fear we will have to find a new game soon.”
As if Izuku wasn’t barely keeping himself out of bankruptcy as is. Nedzu was relentless, no matter the game. He shivered at the memory of the time they’d played charades.
After leaving the principal’s office, Izuku picked up his pace. He would only have missed a few minutes of sparring, and there was nothing stopping him from taking on Shinsou or Hagakure. Not to mention he could keep an eye on Uraraka. Maybe start working out what Nedzu really wanted him to do.
Not that he wasn’t already keeping an eye on Uraraka. Just about everyone was, considering her breakdown last month. Maybe even Nedzu was worried? Was that what this was about?
On second thought, he’d ask Eraserhead if he could just observe today. Shinsou and Hagakure fought him often enough as it was.
Unfortunately, Uraraka had continued to stick rigidly to her pre-Awakening combat style. Izuku had caught Eraserhead’s disapproving eye on her more than once, but even his teacher wasn’t going to push her. Not yet, at least. She’d lost to Jirou, who was adjusting well to the loss of half her quirk, and won against Sero, Iida, and Shouji.
He had more time this week than he’d expected; they’d all been temporarily relieved of duty from the rebuilding efforts last week. Izuku suspected something had happened, but no one had told him anything. At any rate, it meant he was caught up with all his regular classwork and could turn to Nedzu’s project only an hour after dinner.
Aside from her reluctance to unleash her full power, Uraraka seemed normal enough. As did her quirk. He wouldn’t have much of anything new to analyze, but he had to start somewhere. Plus, her old entry was cluttered with all the revisions, as were those about most of his classmates. He’d been meaning to write up clean versions.
No time like the present. Notebook open and pencil in hand, he shifted into analysis mode.
Ochako Uraraka
Hero Name: Uravity
Quirk: Zero Gravity
Type: Emitter
Range: Formerly contact, now undetermined. Reports indicate a kilometer (!!!) at minimum.
Uravity can remove the effects of gravity from objects, canceling their previous inertia in the process. She has displayed an innate sense of these objects and their locations. An Awakening during the War removed her need to make contact with a target along with her previous weight limit. Also absent is her need to connect her fingertips to cancel her quirk. However, she currently prefers pre-Awakening methods of using her quirk. This may be due to a lack of practice, a lack of control, and/or trauma sustained during Awakening. Her Awakening also granted her the ability to gradually remove the effect of her quirk.
UQET Analysis
Magnitude: Uravity is an excellent example of the most common variant of Quirk Extrapolation. Her Awakening featured an exponential increase in weight capacity, range, and precision. This manner and scale of development matches the likes of Endeavor and Dynamight.
Inversion: Uravity has not yet encountered another gravity-controlling quirk to confirm if she could disable that quirk's effects. Only upon her Awakening did she display the ability to gradually reduce the effect of her quirk. No evidence suggests she may be able to increase an object's gravity, though no direct contradiction has been observed. Better cases of Inversion are seen in Shouto and Lemillion.
Narrative: As a direct physics-manipulation quirk, Zero Gravity relies relatively little on the Narrative aspect. However, only the effect of Earth's gravity is negated. Furthermore, the objects from which she removes inertia experience only a fraction of the whiplash that would result if they were halted by other means. Far more thorough cases of Narrative-driven quirks are found in Froppy and Ryukyu.
To investigate:
-Range
-Weight limit
-Inversion testing (assist from Phantom Thief or Rock Lock?)
-Precision with ranged use
And that was it. Done and done.
Nothing struck him as odd, nothing was tugging at his mind or on the tip of his tongue. Briefly he considered going to Nedzu and showing him the analysis, then he snorted. As if.
Whatever his tutor’s game was, it had only just started. Or perhaps it had started a long time ago, and Izuku would have to scramble to catch up.
There was nothing for it, he’d have to talk to Uraraka directly. Izuku didn’t want to make her uncomfortable, but he had no other leads. He’d wait until he could catch her… maybe not alone, but without the usual gossip hunters around. They gave him and Uraraka enough grief as it was.
Izuku got his chance four days later. Most of the class had nagged Todoroki into freezing over the courtyard outside to help them cope with the current heatwave. They were currently enjoying the fruits of their (his) labor. Tsuyu had opted out, given her sensitivity to cold, and Uraraka had stayed in the common room with her.
He lingered around the courtyard for a while, watching various reasons for Eraserhead to get a headache develop, before heading inside.
Tsuyu was flopped over a chair, upside down. She languidly waved at Izuku as he came in, and he returned the gesture. Uraraka was mucking about in the kitchen, and came up to greet him when she noticed his entrance. Very… enthusiastically, almost bouncing as she walked.
“Oh hi, Izuku! What’s up?”
“I wanted to ask- wait, since when do you call me Izuku?”
Uraraka’s smile dropped and she tensed. “Sorry! I just figured… No, no, it’s okay. It’s fine. You can call me Ochako if you want… Not that you have to! I can just keep calling you Deku while you call me Uraraka, that works! That’s fine. Everything’s fine.”
Izuku stared. Out of the corner of his eye, he could see Tsuyu staring too. At him, not Uraraka.
Uraraka was acting afraid of him. He’d gotten used to that from people, during what Ashido still insisted on calling his “vigilante arc.” He knew the signs. That posture, that wariness. Treating him like an animal that could lash out at any second.
He’d never imagined Uraraka, of all people, would ever be scared of him. She'd accepted him when no one else would, twice over.
This didn’t make sense.
And then, Uraraka’s expression shifted into an easy smile. All the tension left her poise. “Hey, I can see you getting lost in your own head there, Deku. Snap out of it, yeah? You had something to ask me about?”
He blinked, confused by… pretty much everything about what was happening right now. “Oh. Yeah, okay. Sorry. First, um. Are you… alright?”
“You know, I think I am. I think I really, really am.” Her smile only grew, and her cheeks flushed slightly. “I’m doing better. You? Er, I mean. Is that all?”
“No, I actually wanted to ask about your quirk, if that’s okay?”
After a pause, in which Tsuyu kept eyeing them from the couch, Uraraka laughed. “Never change, Deku. Tell you what, ask Nedzu if you can skip your private lesson tomorrow and attend combat training. I’ve already promised Bakugou a match, and I figured… when better to really test out my new limits?”
“He yelled at her until she agreed,” called Tsuyu grumpily.
Uraraka nodded, a bit sheepishly. “That too. But he wasn’t mean about it, you know? Not really.”
“Yes, I’m, uh, familiar with how Kacchan communicates.” More than anyone else except maybe his mother, Izuku was fairly certain of that. “And I think Nedzu will agree, he actually gave me an assignment to… well, I’m not sure? But it involves your quirk I think. Or maybe just you, somehow. He wasn’t very clear.”
Uraraka seemed more baffled than alarmed, but Tsuyu’s eyes widened in panic for a moment. Izuku didn’t know what to make of that.
“Oh, um. Well that’s fine, I guess? Anyway, you can just watch me tomorrow and then ask any questions you have afterward.”
“Alright! Looking forward to it.”
“I bet you are,” giggled Uraraka. “I’m gonna go work on some stuff. See you later, Deku, Tsu.”
She gave them a casual wave and vanished up the stairs.
Izuku stood there, processing. What had just happened? Uraraka had been so strange, then she’d snapped back to normal without missing a beat. Almost too normal, even. Something had lightened her spirits considerably since they’d last talked.
“Midoriya.”
He startled and turned to see Tsuyu at his side.
“Go easy on her. She’s not doing as well as she says, kero. Whatever Nedzu wants, she comes first. Got it?”
Tsuyu’s face was always hard to read, but right now, if Izuku had to guess, she was trying to look intense. Or maybe even intimidating.
It was working.
“I wasn’t going to- Of course she does!”
“Kero? Promise me.”
“I promise, Tsuyu.”
“Good.” She nodded. “And you can call me Tsu if you want, kero.”
With that, Tsuyu (Tsu?) headed up the stairs following after Uraraka, leaving Izuku with new questions and all too few answers.
Izuku watched in awe as Uraraka, sparks of her aura drifting through the arena like fireflies, took down Kacchan. Slowly, but thoroughly. In fact, he suspected she was drawing it out to give herself more time to practice. Or give Izuku more time to observe. Or maybe even give Kacchan more of a fighting chance, considering how limited his right arm’s mobility was.
Kacchan realized this at the same moment Izuku did. Uraraka wasn’t quite holding back, but she wasn’t going right for the win, either. Kacchan's retaliation for this treatment was the first solid hit he’d landed, knocking a weightless Uraraka across the arena and almost right into Izuku.
She released her quirk and landed gracefully, giving him a wave before launching herself back into the fight.
Izuku didn’t wave back. He’d started to say something when she’d gotten close, and then all the air had rushed out of his lungs at once.
One of Kacchan’s blasts had ripped a hole in her costume. A gap, showing skin on her left arm just above the elbow. He’d couldn’t help but notice.
Lines. Little white lines. Mostly-healed cuts, or new-ish scars. Four that he spotted in the gap in her costume, arranged neatly in a row on the underside of her arm.
When was the last time he’d seen Uraraka with short sleeves? Even in this heat, she’d always been either in her school uniform or in her hero costume. She wasn’t shy, she’d had no problems showing skin last summer. She was hiding the marks. She’d been hiding the marks. However many there were, for however long she’d been doing that.
He felt sick. And yet Uraraka was grinning wildly, her classmates cheering her on, as she shut down each and every one of Kacchan’s moves. He couldn’t predict when and how she’d alter his gravity, or her own, or any of the projectiles she’d made for herself. She wasn’t even fighting him directly most of the time, just letting him wear himself down trying to catch her while she drifted among the pink pinpricks of light, looking as much like a goddess as a hero.
Izuku barely reacted when Kacchan shocked the entire class by surrendering before he wore himself out. Dully, he watched as Uraraka said something to Kacchan, a smile on her face, and he grinned back and gave her a friendly punch on the shoulder. “I’ll kick your ass next time, Pink Cheeks. Count on it,” he declared loudly.
Even Eraserhead showed rare approval, giving both combatants a nod before calling up the next two. Uraraka practically skipped over to Izuku, sweaty and scorched but smiling wide.
“Still have questions for me, Izuku? I mean. Deku?”
“No,” he managed to squeak out. “I think I got everything I need.”
Uraraka was taken aback, but rebounded quickly. “Okay! Just let me know, I’m happy to help anytime!” She zipped back over to where Kacchan had laid down to rest and started bantering back and forth with him again.
By some instinct, Izuku’s gaze on them abruptly snapped to just behind them, where Tsuyu was staring directly at him.
She looked scary again. Izuku had never thought a frog could be that intimidating.
And then she nodded in his direction and turned her attention back to the next match starting up.
Message received. Tsuyu didn’t want him meddling.
Izuku gulped.
He wasn’t sure if he could stay quiet about this.
He made it six days.
No new cuts appeared on Uraraka’s arms that he saw, but with her covering them at all times, that meant nothing. She kept having those strange moments where she called him Izuku before correcting herself, alongside abrupt mood swings. Not from happy to sad, but from hyperactive and skittish to calm and friendly.
He noticed more oddities: she would look at something normal like she’d never seen it before, or her attention would drift when someone was talking to her, or she would mutter to herself before blushing. Izuku even caught her staring into a mirror for a solid three minutes before shaking herself and moving on.
Something was wrong with his friend. Tsuyu might know, but she’d made him promise to not tell Nedzu whatever he found out. Or at least to make sure Uraraka comes first, whatever that meant. And of course he would.
But he was a hero, even with a fading quirk. He couldn’t, wouldn’t, stand by and do nothing.
He managed to slip away from the others at lunch. They’d assume Nedzu or All Might or Eraserhead had summoned him for some reason or another. His real destination was very different.
Izuku had only been injured twice since semester started, both minor. Recovery Girl hadn’t even needed to use her quirk. She gave him a critical once-over when he strode into her office.
No one else was here. Good.
“Well, you’re not injured that I can see. No offense, kid, but good riddance to that quirk of yours. Not like you needed it anyway. What can I help you with, then?”
“I, um.”
“Spit it out, boy.”
He did, in a rush. “I think Uraraka is hurting herself.”
Recovery Girl stiffened. “Elaborate.”
“I saw some cuts on the underside of her arm, they looked… they looked intentional.”
The old hero closed her eyes and let out a long sigh. “Fool girl. I told her not to test that trick of hers again, but I should know better than to expect one of you children to listen to me. Not that the adults are much better.”
“Wait, what? What trick? What do you mean she-”
“Normally I wouldn’t tell you any of this,” Recovery Girl said sharply, opening her eyes and cutting Izuku off. “I don’t like it. But Nedzu told me you might come by and to answer your questions. I’m not above ignoring him, mind. You keep this to yourself, Midoriya, or there will be consequences. Understand?”
Nedzu had planned for this? Of course he had. “I will. I understand.”
Recovery Girl eyed him behind her visor, eventually deciding he meant it. “Your girl was attacked some weeks back. Nothing she couldn’t handle, just some poor civilian still scared out of his mind by the War who accused her of being Himiko Toga in disguise. She took a puncture wound to her side before she brought him down.”
Concerning, but hardly beyond the norm. “And?”
“And the wound didn’t bleed.”
“...What.”
“My reaction exactly. It took a while to get an explanation out of her, but the short version is that she panicked and used her quirk to control her own body. She was forcing her blood to flow like normal with gravity. Which is a damn idiotic thing to do, but I can’t blame the girl for not wanting to see her own blood after what she went through in the War. But I can blame her for doing it again, on purpose. I expressly told her not to practice it like that!”
Izuku stared.
Recovery Girl starting talking again, but he couldn’t hear her.
No.
That was… that was impossible. Or near enough that even Edgeshot wouldn’t be able to measure the distance between that and impossibility.
State-change emitter quirks had only started becoming somewhat-commonly self-applicable in the last generation, and they rarely displayed full efficacy. Zero Gravity was no exception! Uraraka had worked incredibly hard to reduce the strain from using her quirk on herself before her Awakening. She had no experience with fine-tuning that control, if it were even possible.
Not to mention the extreme mental training that would require. Lemillion’s quirk only self-applied, being a transformation type, and it had taken him years of work with Sir Nighteye to apply it to select parts of his body at will. As far as Izuku knew, even he couldn’t be that precise.
Izuku admired Uraraka. He had believed in her well before he learned to believe in himself. But there was no way she’d mastered her quirk to such an extent in this short amount of time.
So Uraraka had lied to Recovery Girl.
Why?
How was easy enough, at least in theory. Whoever attacked her could have had a quirk that prevented blood from being spilled, or any number of powers that would produce that effect. He didn’t think that was the case, but whatever the cause, it was so much less important than why.
If she’d wanted to hide the attack, to prevent their class from being removed from the rebuilding effort, she could have pretended it was an accident. Recovery Girl wouldn’t have bought it, but Uraraka could have tried. She didn’t, so that wasn’t it.
Was she trying to protect her attacker? No, Recovery Girl said he’d been captured. Izuku could ask Eraserhead about the man’s quirk, but he didn’t think this was likely to be the answer either. And Uraraka wouldn’t frame someone else for anyone’s sake, even if she’d be quick to sympathize with and forgive her attacker if she had the chance.
Was she just trying to make sure no one worried about her? Well, too bad. He was worried.
Uraraka and blood. The obvious connection jumped out at him, but that made no sense either. Quirks didn’t pass like that, even temporarily; he should know, seeing as he had one of the only two exceptions. And besides, Toga couldn’t have done that anyway. Couldn’t have done that before she died.
Unless…
Unless he was missing something.
Toga’s quirk had undergone an Awakening once. For that to happen twice was extremely rare, but much less impossible than Uraraka somehow having mastered precise self-directed gravity manipulation. But there was no reason to expect that her transformation quirk would evolve in a way that would allow her to have a permanent effect on Uraraka.
And while some people apparently suspected otherwise, he knew Uraraka wasn’t Toga in disguise beyond a shadow of a doubt. Even if the resolution of their fight hadn’t been recorded, even if Toga had undergone some miraculous secondary Awakening that let her pass as Uraraka flawlessly without an endless supply of her blood, nothing would prevent Erasure from canceling it. Uraraka’s quirk had been erased multiple times during training since the year began from Eraserhead and Monoma both.
Not to mention that Toga was, again, dead. Tsu and others had seen her die, seen what the cameras hadn’t captured. He knew her body had been retrieved from the battlefield before her death was confirmed to the public, and with Hawks cleaning up the HPSC the chances of any kind of cover-up were nearly-
Something hit Izuku in the head. Not hard, but enough to startle him. Looking up, he discovered the culprit was Recovery Girl’s cane, wielded by the hero herself.
“If that’s all, we’re done here. Quit mumbling and get out of my office,” she barked.
“Right, right! Sorry!”
Izuku rushed off, his thoughts outpacing him even more than usual.
Back in his room, having spaced out during the rest of his classes and rushed past everyone in the common area, ignoring some concerned calls after him, he sat down at his desk and focused. He had a mystery to solve.
Nedzu always tells him to start with what he knows.
What does he know?
What does he know?
What does he know?
All different questions. All leading, if he can find the path, to the same answer.
Izuku shoved his rising exhilaration down. No, he was worried, he was scared, this was for Uraraka, he shouldn’t be getting excited over this!
He got out his notebook and flipped to a fresh page.
Himiko Toga
Villain Name: None*
*Why? Bad family history, warped self-image from trauma, but didn’t take a new name. Lingering attachment? Guilt? Performative shamelessness?
Quirk: Transform
Type: Transformation*
*Minor heteromorphism, standard for her generation and quirk type.
Range: Self-targeted
He stopped and stared at the paper.
No. He didn’t know that.
Quirk: Transform*
*Presumably interpreted and named by quirkist parents/counselors (or the HPSC?), and thus could be inaccurate or at least incomplete. A transformation quirk just called Transform?
Type: Transformation*
*Minor heteromorphism, standard for her generation and quirk type. Degree of mental and physical heteromorphism unclear.
Admittedly, he’d seen… more... of Toga than he’d wanted to, but that still left the possibility open that her quirk altered her internally in ways he couldn’t predict. And even in ways she’d never been allowed to learn about. Izuku hadn’t talked about it with Uraraka in so many words, but he was fairly sure they both knew that Toga’s quirk had altered her mental state.
It was impossible to outright prove, but virtually every modern quirk theorist- including Nedzu, and himself if Izuku counted- agreed that quirks gave their users mental nudges toward their activation requirement. Blood quirks were not just an example but often the first example pointed to in defense of this Narrative aspect of UQET, with nearly every user experiencing some manner of fascination with blood. Toga’s had been both intense and forcibly repressed. Until she snapped and...
Izuku grit his teeth and focused. He could cry over the tragedy (again) later. This was about helping the people who could still be helped. This was quirk analysis, his oldest skill and at one time his only friend.
On the physical side, many blood quirk users showed minor heteromorphism themed after creatures associated with blood. Vampires and similar fictional or mythological monsters, bats, sharks, mosquitoes, even leeches and ticks. The number had only grown as generations passed and quirks become more prevalent and powerful.
It was another Narrative-driven aspect described by UQET. After all, if Vlad King only needed to bleed to use his quirk, then it would be far more convenient for him to have sharp claws. Or even external, flimsy veins. Instead, he had elongated lower canines mimicking vampires. Toga had the same mutation, both upper and lower canines.
This told him nothing he didn’t already know. Yes, Toga had a blood quirk and the associated mental and physical heteromorphism. Nothing unusual there. What he needed to focus on was the nature of her particular quirk. That was the key. What could she do? What had he seen her do? What did he know that she knew she could do?
She can could drink someone’s blood and turn into them. Her body processed the blood in some manner, and the transformation deactivated upon her supply of blood running out. This limitation may have been rooted in heteromorphic traits. Her Awakening gave her the ability to use the quirks of people she has had a strong connection to, as well as control over how the appearance of others manifested over hers.
A fairly standard Magnitude evolution, all things considered.
Wait. What about the other UQET aspects? If her quirk had been misinterpreted from the start…
Inversion: If she takes someone’s blood, she turns into them. The literal opposite of this would be
Izuku’s eyes went wide.
Inversion: If she takes someone’s blood, she turns into them. The literal opposite of this would be her giving someone her blood, and them turning into her.
That was promising. That was very, very promising. But it didn’t explain everything.
Presuming that Toga’s quirk had undergone this particular Inversion evolution, under what circumstances would Uraraka only begin to take on traits from Toga months after the latter died? Why would it first show as an ability Toga herself had never displayed? This didn’t quite add up.
Nothing to do but move on for now. Maybe a Narrative analysis would-
Then it struck him, all at once.
He’d started with the wrong piece. It was the other way around.
Her heteromorphism was the key, not her quirk. He’d been thinking too small. Everyone had been. In both metaphorical senses, when it came to Toga.
Fangs.
Psychological and possibly physiological hunger for blood.
Lack of blood clouding her judgment and increasing both aggression and attraction.
Ability to shapeshift.
Pale skin, inhuman eyes.
A grin crept across Izuku’s face. He knew what she was.
Izuku turned the page in his notebook and started again, from the top.
Himiko Toga
Villain Name: None
Quirk: Vampire
Type: Transformation/Mutant
Range: Self, potentially targeted
She could, or had the potential to, do anything a vampire can do.
As with most Narrative-driven quirks, her exact abilities are determined not by any single source but by common interpretations of vampires regardless of “accuracy.” Froppy, for example, has what would have earlier in quirk evolution be considered multiple separate powers, many drawing from different frog species and some not truly having direct biological counterparts. The latter are instead derived from cultural (mis)interpretations of frogs. Being imprecise, these kinds of powers are prone to becoming mixed-up due to individual development and circumstance. This is seen in Ryukyu, her cultural view of dragons (Eastern) clashing with the particular form of dragon her quirk represented (Western), resulting in something of a hybridization of the two interpretations.
Toga started with the most basic vampiric traits: fangs, a desire for blood, and facial features that read as predatory to baseline humans. With improper support, her desire and probable need for blood went unaddressed and grew over time. Due to extreme mistreatment and trauma warping her self-image, she sought to escape being herself. Her quirk responded, tying together her desire for blood, her desire to not be herself, and her potential for shapeshifting. This resulted in her quirk being labeled incorrectly as “Transform,” giving anyone, Toga herself included, no reason to suspect otherwise.
Her attack on a classmate lined up precisely with two common interrelated vampiric traits: loss of reason when blood-starved, and entering a frenzy at the sight of blood. This lack of self-control was consistent up until minutes before her death, though when stable- that is to say, presumably not blood-starved- Toga displayed the ability to slip in and out of her frenzied persona at will. She could lose that control when exposed to sources of extreme negative emotion, and regain it upon experiencing positive emotion. She had this in common with other Mutant quirks, such as those of Hound Dog and Froppy; consider the former regularly lapsing into canine vocalizations when angry, and the latter’s difficulty with controlling her ribbits when overwhelmed. While explicable by other means, this also supports the interpretation of her quirk as Vampire rather than Transform.
This was it. Izuku could feel it. He just needed to know more. His knowledge of vampires was sorely lacking.
Research time. He pulled out his phone.
From there, it took him five minutes to crack the rest.
Properly tested and trained, Toga could have developed a number of other vampire-associated powers. Using these would likely drain her reserves of blood in the same manner her shapeshifting did, though perhaps not at the same rate. Glamour or minor hypnosis powers are possible, and may in fact have also contributed to the efficacy of her shapeshifting. Already bearing physical features intimidating to humans, she may have been able to accentuate these and induce terror in others. Her above-baseline dexterity, previously assumed to be a matter of training, may have been another part of her quirk. While unlikely to approach the level of a quirk such as Blood Control, Toga could have potentially learned to manipulate blood in some manner. The most likely form of this would be to draw spilled blood toward herself.
Vampires are frequently depicted as having regenerative abilities, most typically using blood to restore themselves from any non-fatal wound. Toga did not display any capacity to self-heal despite sustaining serious injuries multiple times while acting as a villain. She may not have powers of this kind at all, or they have more specific activation requirements. Some vampires are described as able to revive themselves from death (!!!), even from having been reduced to dust*, when their remains come into contact with blood.
*Vampires often collapse into dust when killed. Potential associative link to her clay-like shapeshifting?
Many interpretations of vampires allow them to make other vampires. Whether this can be done unintentionally varies, as does the method. Vampirism in stories is treated either as a disease, spread by biting or other fluid exposure/exchange, or as a ritualistic transformation, in which a human is turned into a vampire by consuming or otherwise incorporating the blood of another vampire (!!!). The latter is the case in one of the founding works behind the modern concept of vampires, in which the vampire performed this ritual and the human underwent a slow mental and physical transformation into a vampire. During this transformation she experienced a mental link with said vampire, and the transformation was reversed upon the vampire being killed.
It is clear that Toga did not grant others vampiric traits (temporary or permanent) by biting alone, nor is it likely she would have ever attempted to “turn” anyone given her complicated relationship with her quirk. However, her death came about as a direct result of transferring her blood to another person: a near-perfect match to the ritualistic method of vampiric transformation. Evidence suggests her quirk may have responded predictably to these conditions.
Izuku threw his pencil down with a cheer. He’d figured it out! Toga’s quirk had been misunderstood, there was no question about it. Quirks kept evolving, kept getting stronger and more complex with every generation. Toga’s growth had been shunted sideways, her potential stunted, but he’d uncovered the truth about her quirk. He’d done it.
Toga’s quirk was, and had always been, Vampire. And that meant-
Warm satisfaction turned to jagged ice in his gut.
No.
He had been so fixated on solving the problem that he… that he hadn’t… he’d just...
Uraraka was turning into Toga.
Izuku activated One For All and dashed out of his room.
