It was 2 days after the sports festival and Izuku hadn't seen Iida since he disappeared suddenly at the sports festival. He had heard what happened to Ingenium over the news and Izuku put two and two together. Iida must be destroyed, his brother had been everything to him. Izuku wanted to go help with Minor Regeneration but it was probably far too late since once a wound heals over it's impossible for his quirk. He knew this because he tried to get rid of a scar he got on his knee when he first received the quirk and he was unable to, if only he had gone with Iida to see Ingenium. God he was so stupid for letting this happen, Iida was never going to forgive him.
Izuku was furiously scribbling in the Journal that had the info on his quirks trying to make himself forget that he could have stopped one of his better friends brother from becoming a cripple. He put so much pressure on the pencil he managed to accidentally break the stupid thing before he threw the pieces against the wall and got a new one.
Quirks currently in possession.
Quirks currently in my possession. Izuku had renamed several of them for multiple reasons, the first being it got annoying when trying to talk about All for One the person and the quirk and his quirk, second by changing the names it'll be less likely that people make the connection of them being a villains quirk previously.
Transfer: Emitter Type Quirk. Allows for the instant transmission of a quirk upon physical touch with the intended target, overuse, too many quirks, or to much usage leads to a migraine from hell and if pushed too far will cause the user to faint. Current limit 15 quirks, soft limit 13.
Ultra Sight: Mutation Type Quirk. Changes eyes of the person who has it to a pure shade of black, passively improves the sight of its user, giving them 20/20 vision.
Night Vision functions in a different way to normal Night Vision it just makes it look like a regular day versus making everything green like regular night vision, he can hold this one for 20 minutes 1 hour before it starts to hurt a bit, the previous user supposedly could keep this up for hours at a time.
Thermal Vision functions as regular thermal vision, turning his vision blue except for heat sources which get redder the hotter they are.
Blacklight Vision Allows the user to see things as if from black light.
Radiation Vision is his least used vision and will probably remain so due to the fact that Izuku wanted to be nowhere near any source of radiation.
Zoom is incredibly useful being able to see about 4 kilometers out, apparently the last user could see up to 5km out, I tried combining it with Thermal once, I regretted that almost instantly however as it felt like my eyes were burning from the strain. After training this with another one of my quirks Tempo I can successfully handle the strain for around 5 seconds.
Dark Vision This vision darkens the world around and causes living things to become a yellow silhouette, this effect only occurs within a 30 foot radius.
Air Cannon: Emitter Type Quirk. Allows the user to fire bursts of typhoon level winds from their palms, with proper practice the quirk can be used to fly, this is by far my favourite quirk. The winds can reach up to 200mph with only 150 mph being needed to lift the average weight person off the ground he wanted to fly so badly. Overuse leads to the person feeling like they have been running for a very long time, he's really glad All Might helped him train his endurance because the stronger the gust the faster you exhaust it, current maximum is 180mphs which he can maintain for half an hour.
Pyrokinesis: Emitter Type Quirk. Allows the user to manipulate any fire within a 30 ft 45 ft radius, it has almost no drawback and allows for free movement of the fire almost perfectly, the only downside is there needs to be a source of fire in the first place. Bakugo is currently in possession of this one.
Fire Breath: Mutation Type Quirk. Allows the user to breathe fire from their lungs that can reach upwards of 800 degrees fahrenheit, the longer the user holds the fire the more injured the throat of the user becomes. Almost completely negated to the next quirk listed, I am only held back by the amount of air in my lungs now, honestly with my skill set I could just pretend I was a fire user at this point.
Minor Fire Resistance: Mutation Type Quirk. Grants the user the ability to withstand up to 600 degree temperatures comfortably, as long as I keep my fire lower than or at that temperature I will be fine and can continually use my Fire Breath and Combustion works incredibly well when combined with the two. I am probably the worst nightmare for a fire quirk user to fight at this point. Huh the thought just occurred to Izuku can I train this? I've never actually tried too what if I just sit in a fire for a while will my heat limit increase?
Silencer: Emitter Type Quirk. When activated the user becomes incapable of making any sound whatsoever. This includes speech, walking, etc. It literally erases sound from the person using it. Overuse leads to the person becoming deaf for a period of time, overuse usually occurs between 20 to 30 minutes. It is indeed the sound made by the user, I screamed at the mirror for like 2 minutes before the feeling of deafness hit me.
Tempo: Emitter Type Quirk. The user activates adrenaline in their body which makes it appear as if the user has either doubled the speed at which time passes or halved the speed at which time passes for the next 5 seconds. The users physical body is still only able to move at their normal speed during these 5 seconds only the mind is able to keep up with the new speed, it essentially allows you to fight in slow mo for the next 5 seconds doubling a person's reaction time, I still haven't found a good use for the doubling of time part of the quirk, well I kinda found a use the other day. I got really bored of waiting so I kept doubling time. Using it for more than 5 seconds without waiting for the 1 minute cooldown time results in a migraine similar to that of being in possession of too many quirks. After intensive training and overuse of the quirk I can now reduce time to .1x speed, i've named this move snapshot.
Minor Regeneration. Mutation/Emitter Type Quirk. He was confused as to how to class this one, since it technically changes his body but it also doesn't have any physical properties, so he just went with both. The user must actively think about healing whichever part of his body he wishes to heal when trying to this quirk, it is not a passive ability. The process at which it does so is incredibly slow and to restore entire parts of the body it usually takes around an entire day. Thankfully they had an example of this already and Izuku didn't have to cut his arm off to find out, since apparently the previous user had lost an entire limb and had it back by the next day. The quirk consumes lipids to heal the body, meaning overuse can lead to malnourishment among other things.
Molecular Vibration: Emitter Type Quirk. Allows the user to control molecules but only as a function of increasing or decreasing their vibration speed. He can speed them up or down causing the object to cool or heat rapidly. He mainly used it on himself to keep his breathing level via slowing down his own molecules and cooling himself down. Theoretically he could melt a person or freeze their insides with this but he has not and will not try that in the future.
Life Giver: Emitter Type Quirk: Allows the user to turn inorganic objects into organic ones. The user essentially splits their soul by giving part of their 'life' to the thing they are creating, kinda like that evil wizard in that really old movie about magic from before quirks. I can currently turn about a fridge's size of things into living creatures before any drawbacks occur.
Wait a minute, Izuku paused while writing about Life Giver, this quirk turns inorganic things into organic things, how does the quirk know what counts as living? Does it even know? Genetic modification was a thing that people had successfully done in the era before quirks. Like that sheep that could spin spider silk, that was a living thing, can I make that? Izuku picked up an additional pencil, okay first try. Turn into a snake with thin bones and wings, Izuku watched as his pencil turned into the very thing he imagined, it floated in the air staring at him.
OH MY GOD THE PREVIOUS USER OF THIS QUIRK WAS A MORON! HOLY SHIT THIS IS SO MUCH STRONGER THAN THE WAY HE USED IT. OKAY, what's the most absurd thing I could make.
Uhh can he create people? He emptied his mini fridge before trying to create himself. Izuku watched as it formed into a naked clone of himself, WHAT IN THE ACTUAL FUCK. HOW DID THE PREVIOUS USER NEVER FIGURE THIS OUT, THIS IS INSANE?!
"Uhh can you talk?" Izuku stared at the naked clone in front of him who merely stared blankly at him. So they don't get clothes but that makes sense, that would be an inorganic material, also so just because it looks like a human doesn't mean it can think like one.
It was at this point a knock came at his door. Okay he did not want people seeing a naked copy of himself so he turned it back into his fridge. "Coming!"
When he opened the door he saw Tenya Iida staring darkly at him. That wasn't a good look he was getting if he was being honest. "Midoriya you possess a healing quirk yes? Please I must ask for your assistance, come with me and try to heal my brother." Iida paused before bowing. "No nor please, I BEG YOU!"
Izuku knew this was coming but how could he possibly tell Iida he couldn't help him? Well it probably won't work but he wouldn't forgive himself if he didn't at least try. "Alright Iida let's go." Izuku turned around and grabbed his notebook, he could finish writing on the way.
"Thank you Midoriya I cannot ever repay you." His bow deepened but his eyes shifted to the notebook. "Is that your quirk analysis book where you examine heroes abilities?"
Izuku paused for a second before figuring he could tell Iida the truth. "Ah - no this is actually the book that list all of my quirks. I was in the middle of detailing all of my new quirks when you visited. I kind of was hoping to finish in the car ride over if you don't mind."
"That is most fine Midoriya, would you let me see the book when you finish? I am quite curious about your quirk and I would be very interested in learning more about it." They had begun walking but Iida was still chopping his hands as he spoke like he always did.
"Oh um I've never really let anyone see this one but if you want to I don't think i'd mind. Although you know pretty much all of them already Iida." Izuku looked curiously at the boy.
"Oh well your quirk is quite the thing Midoriya. It is easily one of the most powerful in existence. You could have theoretically infinite numbers of any combination of quirks. I was simply curious as to your current state." Iida said as he opened the car door for Midoriya before he got in behind the green haired boy. "Driver please get us to the hospital quickly." Iida instructed the person in the driver's seat.
Izuku just shrugged and finished up writing in his notebook quickly before handing it to Iida but he left out his current revelation about Life Giver. He didn't want people figuring that out just yet.
EMP: Emitter Type: All electronics in a 20 foot radius will shut down as long as you remain within that range. There is a staticy feeling the air while this is active, and overuse leads to cottonmouth.
Izuku didn't even realize he's been at 11 quirks for awhile now but the low dulling pain in his skull had stopped.
Izuku got out of the car and looked up at the hospital where Ingenium was being held, god please let this work. He didn't want to fail Iida or see the look of defeat that's currently there anymore.
"We are here Midoriya my brother is on the 2nd floor. I read that your minor regeneration quirk works at a slow pace. I apologize in advance for the amount of time i'll be keeping you here but I promise you I will make it up to you." Iida said as he strode into the building before guiding Midoriya to the room that his brother was currently staying.
Izuku looked into and what he saw was chilling. Ingenium wasn't just hurt, he was destroyed. He was currently strapped to a breathalyzer, his entire body was bandaged and his breathing was weak and short. Izuku began having a flashback to what had happened to his teacher, and he was starting to have a mild panic attack. He could see the man broken, bent, bloodied the nomu pounding him into the floor over and over and over. He felt an arm on his shoulder, he turned to see Iida giving him a knowing look.
"Breathe slowly Midoriya, focus on my voice, in, out, in, out." Iida was trying to calm his friend down.
He started to collect his thoughts and slowly began coming back to his senses. "I'm sorry Iida i'm sure this is harder for you than me and i'm the one who needs to be comforted."
"It is alright Midoriya, I was in a similar state to your own the first time I came here, my brother has been in a coma since the incident with the... hero killer." Iida spit out that name. Izuku had never heard such hatred from Iida before.
"Alright i'll try my best." Izuku walked over and checked if Ingenium could handle another quirk and he could not."Iida I have to take engine first, you should get the doctors ready before I do this in case something happens." Izuku kept his hand on the hero while he talked.
Iida pressed the call button only to see a nurse rush into the room. "Hello ms... Toko. Could you summon the doctors? My friend over here possesses a regeneration quirk but we want to make sure we are safe as possible while we do this."
The nurse was in shock when she heard of such an extremely rare quirk being here, she ran off getting the doctors and returned in the next few minutes. Iida recognized the doctor in charge of his brother from the time he was here, Dr. Ren. "So this boy has a healing quirk, how does it work exactly so we may prepare for it."
Izuku spoke before Iida could say something bad. "It consumes body fat lipids and there is a slight jump at first. We just wanted to be sure you would be at the ready before I tried this."
The doctor paused in thought. "That should be fine he still has enough body fat as for the jump we'll be ready if someone occurs. Go ahead and do what you can lad."
Izuku looked to Iida one last time before he started, Iida just nodded at him. "Alright here goes." Izuku pulled engine from the emaciated hero which instantly caused a spike in the man's heart rate on the EKG but it went down as quickly as it came, Thankfully Iida was smart enough to stand between the doctors and the engines that began growing on Izuku's arms. Izuku sighed in relief before pumping minor regeneration into the man. Forced quirk activation. The familiar green glow of the quirk began sparking all over Ingenium's body. "This will be awhile, my quirk works very slowly." Izuku said to the medical staff.
"Well since it seems fine we will head out but if anything takes a turn for the worse do not hesitate to hit the call button." The doctor said before walking out of the room, the nurse followed shortly after the other man left.
"I cannot thank you enough Midoriya, you truly are a good friend." Iida bowed as deep as he could to the quirk stealer in front of him.
"Don't thank me yet Iida and call me Izuku, we're good enough friends for that." Izuku didn't turn to the boy instead focusing on the task in front of him.
"Then you shall call me Tenya as well Izuku and as far as i'm concerned even if you cannot do anything I will thank you regardless." That was last they spoke for several hours, instead Iida let the boy focus on his task instead of distracting him further.
Five hours into Izuku's operation he was beginning to sweat, he didn't know how painful keeping someone else's quirk going for this long would be. This was excruciating, using transfer for this long was destroying him. His head felt like it did whenever he hit his quirk limit. But then he looked down, the man below him had become extremely thin but he could not see any other differences. He knew it, he couldn't help Ingenium. Izuku reluctantly released his hold over Ingenium's given quirk before falling backwards towards the floor.
Tenya noticed the struggle the other boy was going through and made sure to catch him as he fell. "Izuku are you okay?!"
"Ha...Ha...Ha... well I learned something new about my quirk today. I'm sorry Tenya I think this is the most I can heal him, I didn't want to tell you earlier but it can't heal older wounds. I'm sorry for giving you false hope." Izuku struggled to stand he saw the dark expression on his ...friend? I don't know if he'll still be after I lied to him like this. He stumbled over to Ingenium before taking regeneration and giving his engines back. The heart rate spiked again which caused the nurse to come running back into the room several moments later.
"Sorry , when I stop using my quirk the same thing happens as when I start using it." Izuku dejectedly spoke to the nurse.
"That's fine but did you do it? Is he healed?" The nurse more worried about her patient than anything else.
"A little bit I don't know honestly. My quirk doesn't work on wounds that have already been sealed." Izuku looked down after that but the doctor broke into the room shortly after as well.
The doctors face visibly shook. "Lad you did it, his spine it was supposed to be permanently destroyed. My quirk is called X-Ray i'm sure you can figure out what it does." The doctor walked over to the man in the hospital bed rubbing his hands over the stomach of the man. "It's completely fixed I cannot believe it. He might be able to walk again, true many of his wounds are still irritated and not fully healed but he's much better now than he was before." The doctor jumped when he heard a groan below him.
Ingenium opened his eyes slowly, dear lord he was hungry. Oh this is the hospital, guess I lost to Stain, god everything hurts. He lifted his head to look down at his ruined body he tried to move all parts of body. They all still work, thank you for that at least modern science. He began weeping before noticing the room was full of people. "Oh I suppose i'm not alone am I?"
Tenya Iida stared at his brother move his legs and arms, his dear brother. He couldn't hold back the floodgates he rushed the pro hero before pulling him into a hug. "Tensei you're okay I can't believe it! I couldn't handle it if I lost you."
Izuku and the medical staff felt like they were intruding in a moment and quietly left the room. spoke once they were out of the room. "You did something amazing lad, would you mind giving me your name? We could use your help at our hospital."
Izuku couldn't believe that he'd managed to save Ingenium, he really thought he had failed. "Oh it's Izuku Midoriya sir, but like I said my quirk won't work on old wounds and i'm not allowed to leave U.A. without a supervisor so I don't think I could help all that often." He rubbed the back of his head as he said that.
"Well thats a shame Midoriya, you have a truly wonderful gift. If you ever decide you want a job we'd gladly extend you an offer." The doctor spoke with a sad look in his eyes.
Tenya decided to come out of the room at this moment. "Izuku please come in my brother Tensei wants to meet the person who gave him his life back."
Izuku just silently followed Iida into the room before he spotted pro hero sitting up with his back against the hospital bed and Ingenium was smiling at him. "So you're the Midoriya Tenya always talks about huh? I can see just why he likes you so much but I thought your quirk was an air cannon quirk? I saw part of the Sport's Festival before my ... incident."
Midoriya and Iida were freaking out, they couldn't leak Izuku's real quirk so he went with the best option he had. "Ah I actually am a dual quirk user like Kirishima and Todoroki, err the guy who could make fire and ice and the guy who could harden and jump long distances."
"Oh that makes sense, I guess you just didn't have a chance to use it much during the Sport's Festival." Tensei just started laughing. "Besides, how could I possibly grill the person who fixed my spine. When I woke up I was sure I was done as a pro hero but at least I still have a chance now. I'll probably need to do some physical therapy, I heard that it sucks so not looking forward to that." Tensei looked up and off into the future when he said that. "But anyway Midoriya tell me about yourself, Tenya's told me a lot but I wanna hear more about you."
Izuku wasn't a bad judge of character but Iida's brother was interesting to say the least and he could not get a read on him. "Well I worked really hard to get into U.A. I really like quirks, i'm currently dating one of my classmates, i'd consider myself pretty outgoing and a generally relaxed person but i'm able to get serious when I need too. Is there anything in particular you wanted to know?"
"No no that's fine. Did you win the sport's festival? I had to stop watching when the tournament started but before that, you and the girl I assume is the one your dating were crushing it." Tensei smiled at Midoriya brightly.
"Unfortunately no but we both got to the finals where I ended losing to her. She's just too talented honestly and once she made that suit of armor there was nothing I could do. I can't say i'm mad about losing though, getting 2nd was good enough for me. She's just so amazing." Izuku smiled while talking about Momo.
"You must really like her then, make sure treat her right okay? Anyway i'm absolutely exhausted and starving, so i'm gonna ask you two to head on home. Keep my brother safe you hear? I won't forgive you if you don't." Ingenium's smile went dark as he said that.
"Of course I'd never let anyone hurt him." Izuku panicked at the sudden change in atmosphere only to see Ingenium start laughing.
"I'm just messing with you, of course you will. Have a good day you two." Ingenium waved them off after that.
Outside the room Izuku spoke to Tenya. "Your brother is... interesting. If you two weren't basically carbon clones of each other I wouldn't think you two were related at all."
Tenya beamed when Izuku mentioned his brother. "He is a most excellent older brother he is carefree and a good person, he's saved so many people and I'm so proud to be his brother but I must admit you are right. Personality wise we are very different, i'm uptight and a rules follower and he is the exact opposite."
Izuku stared at the boy before responding. "...Yeah, but still he's a good guy and so are you. Alright let's get back to campus i'm hungry after that. Holding up my quirk for 5 hours was exhausting."
Once the car dropped Izuku back off at campus he received a call from the principal and Izuku immediately realized he had forgotten. He was supposed to give the principal his notes on hero analysis today, shit. "Hello Nedzu."
"May I ask where you've been Izuku? I remember specifically mentioning to you to not leave campus without letting me know beforehand." The principals voice was calm but nowhere near reassuring.
"I'm sorry sir, Iida asked me to try and heal his brother and I couldn't not at least try. I'll take whatever punishment is necessary but I don't regret my actions." Izuku had to stand strong at least for this.
He was met with cackling laughter. "Of course I knew where you were, I was just messing with you. I had Eraserhead following you two which i'm sure he's not happy about but I had to keep you two safe. Anyway get your notes and come to my office. Also did you succeed?"
"Yes sir."
"Very good Izuku I can't wait to see you." The phone line cut, well shit he's sure that Aizawa-sensei is going to get revenge for this.
In the principal's office. Izuku was watching the animal look through the analyses he requested from Izuku, his eyes were rapidly shifting up and down the pages at a breakneck speed that impressed him to no end. After about 10 minutes the creature stopped set down the papers and looked up.
"Good work as always Izuku, i'm proud that you've been taking this seriously. I will admit there are many humans I do not like but you may count yourself as one of the few I do." The rat hummed as he spoke.
"Well thank you sir, and i'm sorry I left without telling you." Izuku paused, something had seriously been bothering him but he didn't want to bring it up with the principal, of course however the creature noticed his distress.
"What is wrong Izuku? There's clearly something on your mind." The mouse quizzically looked at him before urging him to continue.
"Nedzu I think we have a traitor in our midst. The villain's specifically mentioned the class schedule and the only time they would have been able to enter the building was the media outbreak. I don't want to doubt my fellow classmates but some things have been seriously bothering me." It was nowhere near concrete evidence but they do say an event happening more than once isn't a coincidence it's a pattern. "Sir what is Hagakure's quirk classified as?"
The sentient animal shook when he heard the name of the student in question dropped. "Invisibility, as simple as that. Why do you ask and what made you curious about her quirk? These are not light allegations Izuku."
"Well it's nothing concrete, it's all circumstantial evidence but i'm sure you know the saying three's a pattern. The first thing was on the day of the U.A. break in when I counted the votes, right before the alarm went off there was only 18 votes for the vice class rep which implied someone simply didn't vote, the other missing vote was myself obviously but that's where it gets interesting. I checked the other day and when I had everyone line up to check if they could handle extra quirks Hagakure wasn't on the list. I didn't notice at the time because I hadn't known everyone for that long but when I checked the attendance she was there that day so at some point she left the room without telling anyone then returned for attendance after the alarm had been turned off."
"On top of that at the USJ she claims to have been with Todoroki but as Todoroki himself stated, he blasted everyone around him with ice so she couldn't have been there without being frozen which means she lied, the question is why? Lastly at battle training it seems her quirk is an emitter type not a mutation quirk, she REFRACTED light, that has nothing to do with being invisible, UNLESS she's constantly using it on herself. All of this is merely conjecture and I know it doesn't make sense since the enemy didn't know about my quirk when they attacked at the USJ and Hagakure definitely knew what my quirk was. However, that being said Tsuyu and Bakugo were sent to the zones they would be best in so she may just have not told them about our quirks." Izuku watched as the face of the creature before him darkened more and more.
"...That is an interesting hypothesis Izuku, I will admit I have been entertaining the idea of a traitor myself. Well there's a way we can find out, let me pull up the security footage from the day in question. I'll put the camera that watches the doors to your classroom on the left and the one that watches the door that leads to the teacher's lounge on the right." The mouse fiddled with his keyboard while setting up the views in question. "I'll fast forward to the point in question." Izuku watched as the camera's timer rapidly counted to 11:58 am before Nedzu returned them to normal speed.
After ten minutes had passed nothing occurred and Izuku's idea was thoroughly crushed,... or so he thought. "My my this is interesting, have you noticed Izuku that both of these cameras stopped broadcasting what was currently happening, if these were correct we would be seeing you and Yaoyorozu enter the hall from your classroom right about now but we aren't. It seems like these two cameras in particular have been tampered with, I can't believe I missed this. I hate to say it Izuku but your theory is starting to look more and more true. I will begin looking into Toru Hagakure as a suspect working with the League of Villains." The mouse pulled out his phone tapping into before a voice came through.
"Hello principal Nedzu this is Detective Tsukauchi."
"Ah yes there is something I need you to look into, tell All Might as well but no one else. It has come to the attention of myself that we may have a traitor in our midst. I want you to start looking into the background of one student Toru Hagakure, in addition I would like for you to sit in with a meeting with her in the next few days like we had you do for Todoroki." Nedzu was shaking while he said this.
"Do you have any proof before I start this Nedzu? I can't just start digging into the background of a girl without some real evidence." Tsukauchi sighed, of course with Nedzu he probably had something already, he wouldn't be surprised at least.
"Nope not in the slightest, we've just noticed her behaviour is quite odd in addition to her lying to the staff on multiple occasions. Not to mention her quirk registry form is incorrect, as her quirk is not invisibility but what we believe to be light refraction." Nedzu said returning to his chipper state.
"I... see, well your not wrong that's nothing concrete but it's enough to make me interested. I trust you Nedzu, i'll begin my investigation immediately. Anything else you need?" The detective knew things were never easy when Toshinori or Nedzu were involved.
"No that is it for now. Have a good day." Nedzu just sighed once it ended. "I'm sorry i'm running through multiple phases of shock as I adjust, Izuku I have a task of you since your the only one who can actually see the girl. Keep an eye on her but be discreet. Do not risk scaring her off, if she is a spy she will likely have information we could use to catch the league."
Izuku just nodded. "Of course Sir, I can keep thermal up for quite awhile now and dark vision can spot her as well. I'll do my best." With that Izuku was dismissed, his mind was reeling. He just hoped he was doing the right thing.
As soon as he exited the room he ran into his teacher, he was glad to finally see the man out of those bandages. "Oh sensei, I'm sorry I didn't mean to run into you."
Aizawa simply stared at the child before him before responding."...Problem Child I heard everything, are you sure everything you said was accurate?" Aizawa was giving Izuku a glare that meant he better be serious about this.
"Yes sir, that's why I was hesitant to bring it up. I didn't want to believe it possible that one of my classmates was doing something like this but I couldn't just keep ignoring the feeling I had in my gut." Izuku returned the gaze his teacher was giving him, letting him know he was dead serious.
"I'm going to talk to Nedzu about this, keep your head down and don't do anything suspicious. Tell no one, not even Yaoyorozu do you understand me? Also don't think I don't know you two are sneaking into each other's rooms all the time. I trust you both not to do something stupid, that's the only reason i've allowed it so far do not prove my trust misplaced." Aizawa's quirk flared up when he said that last part.
Izuku panicked at first but once he realized he was not in trouble he recovered. "Um sensei I didn't tell Nedzu but there might be an easy way to prove if she's lying. Just let me steal her quirk I can just lie and say it was an accident and if I turn invisible as well that should clear her name but If I remain visible, well... then we will have confirmed a pretty large part of our theory."
Aizawa stood in contemplation for a bit before responding. "I'll ask Nedzu and get back to you later tonight, just keep your head down for now. Got it?"
"Yes, sensei." Izuku walked away after that.
Aizawa sighed and faced the door, of course if anyone was going to find out about a potential mole it'd be the problem child. He knocked three times before entering the room.