Bakugo couldn't believe his eyes, there was no way, absolutely no way that all of this was happening. He watched as the girl he'd known for months smiled at him in a wicked, cruel grin, knowing she had just played him.

She couldn't be serious, all of those days, all of those encounters and conversation were all just for his damn student ID card? Did that mean that everything she had said back then was a lie also? His first kiss, she took it as some kind of award for her plan. The very thought alone made him sick.

Katsuki couldn't even look at his classmates as they all stared at him. He just felt so stupid and idiotic for letting that girl do what she pleased. Bakugo knew he should've been smarter than that, but even now he was held captive by her gaze, her words. They haunted him.

Everyone watched as Aziawa raced past them, his eyes glowing red and his scarf gripped in his hands as he went to attack the female villain. The man seemed to have a sense of desperation as well. "All this time..you were alive?"

Sienna only threw her head back though, enjoying the confusion on his face as he approached. "Yep, sorry to disappoint. Looks like your little case wasn't so wrapped up in a neat little bow after all. Oh, you must be disappointed. But I'm sure that paycheck was worth it, wasn't it?"

Aziawa frowned as he threw his scarf out, eyes locking onto her quirk before answering back. "I never knew, but this time, I will save you, I won't let them use you like this."

His weapon descended but was suddenly stopped when Sienna disappeared through a large purple portal that had materialized behind her, shallowing the girl whole. Where did she go?

The man froze at her disappearance and whirled around only to hear soft laughter a couple feet behind him. "I hate to break it to you sensei but I don't want to be saved anymore. I gave that up a long time ago, when you heros abandoned me."

Aziawa's eyes fell in devastation now seeing the girl standing on one of the USJ props, towering over the entire arena with interest. After a moment, Shigaraki angrily called from below her. "Finish up your reunion already. Just because All Might isn't here yet doesn't mean he won't come if we kill a few kids."

Sienna gave a sickening smirk at that. "True, do you want to try it out?"

Nodding his head, Shigaraki replied. "Just hurry up brat."

Rolling her eyes in response, she didn't like the authoritative tone he gave, but complied anyways knowing their goals were the same. "With pleasure, boss."

Sienna then let in a huge breath as she locked eyes with Bakugo before a smooth and haunting melody filled the entire area, flowing into the students ears and making their bodies heavy and lethargic. It was like a pile of lead bricks were weighing them down, suffocating them slowly.

Aziawa seemed to notice this and immediately covered his ears, shouting at his students in the process. "Don't listen to it! Everyone cover your ears or her quirk will affect you!"

The students listened as Bakugo started to feel his eyes close in a drowsy nature before doing the same. The minute his ears muffled the sound, his body felt lighter, if only a little. Her song still felt like it was pushing its way into his soul, but at least now it didn't feel like the boy was going to pass out.

Deku seemed to notice this as well, covering his ears and gapping at the girl. "Her quirk, it's like some sort of siren song or something. Kacchan, how do you know her?"

Shaking his head, Katsuki willed the memories from his mind, grunting back. " Screw off Deku! I don't know her, she's just some extra. Not worth my time."

He said that, but of course Bakugo didn't fully believe those words. She wasn't just any extra to him. They had known each other for months, some would even categorize them as friends. But now, now he didn't even know who she was.

Deku could see the struggle in his friends eyes and almost went to call him out on it, except Aziawa beat them first, quickly shouting back. "Find your way to an exit, radio for help, stay out of trouble and don't uncover your ears. I'm going to finish this."

He put his goggles on then before racing ahead of them, the students just looked bewildered at what was happening. This wasn't any old test, this was a villain attack.

Suddenly, that familiar purple mist appeared behind them once more, chuckling softly at the display. "Now, it's a pity that All Might can't be here today. Was there some kind of change?"

Grumbling back, Katsuki took his chance quickly, now aiming a fist towards the villain in anger just as Kiri did the same. "Take this!"

Throwing their fists down, the two were surprised when they passed right through the villain, falling to the other side as it laughed. "Oh dear, that's dangerous. That's right, even if you are students I can still scatter and torture you to death!"

Just then the wrap grew, reaching to massive size before swallowing the entire class whole and sucking them into the purple void all at once.

Sienna eyed the altercation as she sang and internally hoped that Bakugo wouldn't die. She asked him not to anyways. It really would be a shame if he ended like this.

Her eyes fell a little at the idea and Shigaraki seemed to notice, a small bit of malice in his voice. "What, are you worried about the boy? That's not like you."

She just shook her head though, annoyance in her gaze. Worried? No of course not. She would never be worried for a hero. Shigaraki was right, that wasn't like her.

Sienna stopped her thoughts when she saw Aziawa running up to him, intent in his stance. That's right, it wasn't time for this. She needed to get serious and do what she came here for. Revenge.

Bakugo felt himself being dropped through the roof of a large building before crashing onto the ground, groaning as he did so. Shit, why did that villain have to drop him like that?

Shaking himself off, she heard another groan next to him only to find Kirishima a couple feet away. "Geez, that villain was serious business. You alright Bakubro?"

The boy nodded his head once in response, grunting back. "Of course I am stupid. Where the hell even are we? Is this one of the simulations?"

Kiri shrugged back only for the door next to them to slam open as a hundred or so men filed into the room, now surrounding the two. "Aww man. Looks like we are going to have to fight our way out."

The villains leaped forward only for Bakugo to punch one of them in the face roughly. "Just don't slow me down shitty hair!"

His friend smiled back before getting to work himself, noticing that the villains were extremely easy to take down. It was like they were just some common thugs.

Punching another one, Kiri had another question come to his mind. "Hey Bakubro, who was that villain before? You acted like she knew you."

At the word villain, Katsuki flinched before throwing a huge explosion in his opponents face. He didn't mean to use his quirk that much but just the idea of that girl brought a hot, unmistakable rage in his stomach. "I don't know that extra. She's nobody."

His friends immediately got different vibes from his words but Kiri wanted to respect his wishes. Bakugo knew her somehow, he just knew it. "Ah alright. If you say so. We should get back to Aziawa sensei. Who knows what he's dealing with. That girl seemed like no joke either. Her quirk was kind of scary."

Once again, at the mention of Sienna, Katsuki felt his fists tighten in fury. "When I see that extra, I'm going to make her regret ever screwing with me! She messed with the wrong hero!"

Kiri blinked in surprise as he then watched Bakugo move towards the exit, intent in his step. That proved it, Katsuki did know that girl, pretty closely also it seemed. Otherwise his friend would have never gotten so fired up about her.

It made him wonder just what she was to him.

Sienna watched Aziawa fight the Nomu's and Shigaraki with a blank expression, still intensely thinking about that annoying blonde porcupine boy. Was he dead by now? She was honestly curious to know the answer.

Her quirk made the hero's movements slower, the girl's song seeping into his mind and silently telling the man to become weak. This was almost too easy, if only All Might were here though. Then it would be perfect.

She exited her own thoughts as the Nomu reached up behind Aziawa before slamming its body on top of him before grabbing one of his arms and twisting it behind his back under a loud sickening snap now overheard throughout the space.

Sienna stopped her melody and the man felt the energy hammer back into his body, using the opportunity to try and use his quirk, reaching out towards Sienna only for the Nomu to break his other arm.

He cried back in agony as Shigaraki smirked back. "Goodbye hero."

Although he paused when Sienna spoke right after him, halting the Nomu. "Wait.."

The villain eyes her curiously as she jumped down from her spot before carefully strolling up to Aziawa with hallowed eyes. "Now how does it feel to be forgotten, sensei? Your little hero friends aren't going to come for you this time."

As the blood dripped down his face, the man sputtered back brokenly. "Shi.."

Although Sienna just cut him off, waving her finger. "Ah ah ah, I don't go by that anymore, so don't even try. What a pity, it looks like it's the end of the line for you, Sensei. I guess that paycheck didn't mean much after all, did it?"

His eyes widened as she laughed to herself, signally for Shigaraki to continue when suddenly she felt herself getting punched in the face, causing Sienna to hold her jaw in pain. "What the hell.."

Refocusing her eyes, she blinked only to find Bakugo standing in front of her, intent in his stance and anger in his gaze. "You...you bitch! If you think you can screw me over and live then you have got another thing coming to you!"

She held her jaw only to place her hands on her hips. "Ah Katsuki, good job. You listened to my request. I was beginning to think you died already. How disappointing that would be. Although I knew you were stronger than that."

Bakugo didn't share the same feelings though, lifting his hands up to ready a large explosion. "Damn right, and I'm going to make you sorry for messing with me extra. All those months, all that damn harassing was a joke?! Don't fuck with me Sienna!"

Nodding her head, Sienna replied plainly. "Well duh, I needed your ID. No hard feelings though, I really did have fun playing around. Plus, kissing you all those times was a major plus."

She winked back as Katsuki seethed in fury, throwing an explosion in her path only for her to be swallowed by that small purple portal again and appearing behind him. "Oh, you wanna play? Alright, I'm game."

Bakugo gasped and turned around to throw a punch only for Sienna to catch it and throw one of her own. "You're gonna have to try harder then that Katsuki. Once again, I'm still not impressed."

He frowned then, dodging her advances before throwing another explosion in her path, Sienna jumping back in surprise as he shouted. "Screw you! Stay still so I can kill you!"

Shigaraki's voice entered the space then, interest in her tone. "You're taking too long Sienna. Stop fooling around and finish the job already. Would you like me to kill him for you?"

For some reason, Sienna didn't like that idea though, only huffing back. "And take my fun away? Oh hell no. Don't you even dare crusty lips, Katsuki is mine."

He didn't know why, but the last part of her sentence made his heart hammer in his chest with uncertainty. What the hell was he even thinking right now, she was a villain, and trying to kill him. Bakugo needed to get his head on straight.

Just then a flash of green showed in the corner of her vision, and Sienna turned to find that goody two shoes hero wannabe trying to drag Aziawa away from the fight unnoticed. "Come on Aziawa sensei. We have to get you out of here."

Narrowing her eyes, Sienna opened her mouth then only for her melody to seep through the space once more, Deku's eyes growing heavy from the pull. No, he couldn't fall unconscious now, he had to save his teacher.

The green haired boy's movements slowed and Sienna smirked only for Katsuki to throw another swing, this time not as heavy though, given her quirk effects.

She easily grabbed it before throwing a hard fist into his chest, the impact hitting more forceful than before and Bakugo felt all of the breath leave his lungs. Her song made him feel like he was suffocating on his own loss of air as he pummeled to the ground.

Sienna eyed him from above with a bored expression before moving when a Nomu approached behind Katsuki as he struggled to stand, the monster raising his fists up to the two of them with intent.

She quickly flashed her eyes towards Shigaraki who smirked under his breath, knowing exactly what he was trying to do. He was going to kill Bakugo, even though Sienna clearly told him not to. That son of bitch, he just wanted to see her reaction.

Feeling her breath pick up faster, everything flew in slow motion as Sienna watched the Nomu bring his fists down in terror. Wait, terror? Why was she so afraid, so bothered by this boy's death? She had never cared about anything like this before. She didn't like it.

She could very easily jump out of the way and avoid the hit as the girl was still able to stand, now eyeing Katsuki who was still struggling to gain his breath back from her quirk. He wouldn't be able to dodge them in time, the Nomu would kill him before he had the chance.

Bakugo seemed to notice the attack as well, reaching his fists up to let off a massive explosion in hopes that it would quell the hit, the smoke filling the area all at once. "Damn it!"

The boy saw a large hand reach down and he shut his eyes, waiting for the impact before feeling himself get shoved away from the blast zone, falling to the ground in a heavy thud.

Deku screamed at the loud pound and raced forward past the smoke only to find Bakugo on the floor a couple feet away, coughing at the smoke in his lungs. "Kacchan! Are you okay!? What happened?!"

Grumbling back, Bakugo narrowed his brow in confusion only for the dust to clear as the large stone wall behind them started to cave in on itself, a small body laying in the center of the debris from the attack. "What…"

Katsuki's eyes widened in confusion as he saw Sienna, bloody and unconscious a couple feet away from them, now knowing that she was the one that got caught in the Nomu attack. But that then begged the question, what saved him from joining her?

Shigaraki frowned when suddenly a loud voice boomed through the air, causing every villain to freeze. "Don't worry, because I am here!"

They all turned towards the entryway only to find All Might towering above them, intent now in his stance as he eyed a broken Aziawa and then a very familiar girl to his right that made his heart drop into his chest all at once.

No, it couldn't be.

When Sienna awoke she was met with a clear glass holding cell and soon after found herself handcuffed to a small table in front of her. In the process they placed some sort of necklace on her which seemed to be some sort of quirk destabilizer or something. Just wonderful.

She waited for a couple more minutes when a man walked in that made her want to gag just looking at him. Of course he would be the one to interrogate her. "Oh just fucking great, it's Mr. I'm Here. All my hopes and dreams have been answered."

All Might eyed the girl's sarcastic tone before sitting in the chair next to him. "It's so wonderful you see you again Young Shi…"

But before he could finish his sentence, Sienna spoke over him, a slight bit of malice in her tone. Why was everyone using that name?. "It's Sienna, and only Sienna. That other name is nothing to me anymore."

The man didn't fully understand her words but respected them nonetheless, knowing he'd get nothing out of her without it. "Young Sienna, you don't need to worry. We will protect you from the league of villains. They won't harm you ever again."

Sienna blinked in disbelief for a moment before laughing back. "What is with you two? First Aziawa sensei and now you. I don't think you get it All Might so let me get this through your thick skull. I wasn't kidnapped or anything. I chose to go with the league. I'm one of them now, so sorry to disappoint."

All Might's eyes widened at that, not believing her statement. "Young Sienna, that can't be true. You were in the hero course before you disappeared. Those villains must have threatened you in some way. It's alright, you can tell me."

At this, Sienna's brow turned to one of anger, slamming her fists on the table as she shouted back. "You wanna know what happened to me All Might?! When I was kidnapped by those villains I held onto that hope that you would find me,that you would stop at nothing to get me back to my family. I waited day after day with the hope that the heros would save me. But after it became too difficult for you, you gave up and told everyone I was dead just so you could fucking collect a paycheck and get your god damn hero credit!"

All Might stood silent at that. What she said was true, he made the call to declare her dead even though they hadn't found a body. The man just assumed that she would've been killed by the time he reached her. He had no idea that Sienna was actually waiting for him,counting on him. He let her down. "Sienna..I…"

Although she only shook her head. "Save it. I don't want to hear your fucking excuses or apologies. Honestly, I'm over it. So just throw me in prison or kill me already, I don't care. Just do it quickly."

The hero felt a heavy ball of emotion rise up in his throat at her words. This girl, he had only seen her once or twice but looking at her now, it seemed like all the life had been beaten out of her eyes. She clearly wasn't the same person that he had seen a year ago.

Just then, a woman walked into the room before whispering something to All Might, the man nodding his head in agreement. "Yes, it's alright, send him in."

Sienna eyed the hero with confusion at that. Someone was joining them? That couldn't be good.. "Send who in?"

All Might looked down at her file then before sighing. "You were missing for a year Young Sienna. I had to inform your family you were alive."

At his words, the girl felt her heart drop in her chest. Oh no, anyone but him. She didn't want to see him, especially like this. "All Might...please tell me you fucking didn't…"

But just as she said that, the door slammed open with a loud thud, Sienna laying her eyes on a boy she thought she'd never see again, and for good reason.

He looked to have just seen a ghost, the boy's expression hollow and in absolute shock as sweat matted his matching purple hair as Shinso gasped. "...Sienna?"

Groaning back, Sienna muttered. "Oh boy, here we go…"

Then she snapped her face back to meet his eyes, the familiarity in them bringing up some annoying and unwanted memories. "Hello little brother, long time no see."

He stood there in silence, like he couldn't really believe what he was seeing before heavy tears made its way to the surface. "I'm dreaming, this can't be real. You're alive?"

Nodding her head, Sienna only sighed. "Last time I checked yeah, you've really gotten dumber over the years haven't you Toshi?"

A small sob escaped his throat then as Shinso raced forward and wrapped his arms around his sister, much to her discomfort. "I can't believe it. You're really here. Sienna, I thought you were dead."

She let him hug her, mostly because she didn't really have a choice, Sienna shaking her head under his shoulder. "Yeah, well you thought wrong. Now, let me go already."

He compiled and released her only to notice her handcuffed to the table and a quirk suppression collar around her neck. "Hold on, why are you tied up like that?"

Sienna remained quiet for a moment, dreading the conversation she was about to have. This is exactly why she wanted him to think she was dead. She wasn't sure if she was ready to see her brother's ashamed eyes just yet. "I'm not your sister anymore Hitoshi. She died a while ago."

Shinso twisted his brow in confusion, not understanding what she was saying. "What are you talking about? Of course you're my sister."

Groaning back, the girl hissed. "That's not what I meant. I'm not a Shinso anymore. I gave up that name already. They didn't tell you why I'm in here, did they? I'm arrested for helping aid in an attack against the heros."

The boy stood silent at her words, now feeling like poison on his tongue. That didn't sound like his sister at all. The girl he knew worshiped being a hero more than anything. "What, why would you even do that?"

That's when Sienna laughed, low and empty. "Because I'm a villain."

Shinso felt his heart drop in his chest at that. No, there was no way. "What.."

Shaking her head, the girl only smirked back, empty and hollow. "You heard me. Do you remember what our classmates used to say about us, about how our quirks were better for a villain? Well, I took their advice."

Her brother couldn't believe her words, he just couldn't. Sure kids used to pick on them for their quirks as they were very similar in terms of brainwashing, but he never would've expected her to actually agree with them. There was something wrong, something happened to her.

Then he remembered the news stations and the heros explaining her disappearance that happened last year. They concluded that she was kidnapped because of her quirk, but it was never revealed who her kidnappers actually were, or how she got away.

Shaking his head in disbelief, Shinso muttered back the confusion in his mind. "W-What happened to you?"

Sienna only shrugged her shoulders though, answering plainly. "Torture."

Her brother widened his eyes at her response only for the girl to laugh it off like it was nothing. "Oh please, don't look at me like that. Trust me, after like the fourth week I got used to it.

The boy felt bile rise in his stomach as he continued his questioning. "You're not serious, right?"

Sienna only gave him a knowing look though. "If that makes you feel better, then sure"

She laughed again and Shinso wondered what she could have gone through to make her so deranged, so broken. There was something wrong with her now, it was like she had completely lost her mind to those kidnappers.

Just then, Sienna slammed her hand on the table towards All Might like she was about to order a meal. "Alright, this family reunion is great and all but if you're going to lock me up, can you just do it already?"

The hero seemed to be dumbfounded though, sputtering out his response. "Don't you want to spend some more time with your brother? You haven't seen each other in a year.."

Although Sienna shook her head in response. "Yeah not really, I think I'm good."

To that, both All Might's and Shinso's eyes widened in shock, her brother feeling a new sense of pain from her words. "Sea, what has gotten into you?"

At the same time as her childhood nickname, the girl faltered, now remaining silent as All Might replied for her. "I'm sure Young Shinso has just been through a lot and is not thinking straight."

Her last name made Sienna groan in annoyance though. "I said don't call me that.."

Shinso's eyes fell at the rejection when he suddenly felt All Might's hand on his shoulder. "If I might speak with you for a moment?"

The boy listened and reluctantly left his sister alone before hearing the hero talk sadly. "I believe those villains really did a number on her Young Shinso. It seems she's forgotten her previous dreams of being a hero."

Shaking his head, Shinso replied. "Something must have happened. If only I had been there for her, then things wouldn't have turned out like this.."

He put his face in his hands as All Might touched his back in support. "Now now Young Shinso, I understand your distress but we have to discuss the matter of her crimes. She did try and aid a villain attack. I'm afraid she may be too far gone to save now..."

Shinso's eyes fell in devastation then, his eyes welling up with tears when suddenly a new voice entered into the area, desperate and out of breath. "All Might, wait!"

Turning his head in confusion, All Might turned to find Deku running up to them. Because this wasn't a prison it was easier for visitors to enter the facility. He must have used the All Might name to get in. "Ah Young Midoryia. What is it?"

Huffing on his knees, Deku spoke back. "It's about that girl, the one from the villain attack. What are you going to do with her?"

The hero replied back shortly. "Ah yes, we were just speaking about her possible punishment, even though he hoped there would be another way. Although we can't deny her villain tendencies, even if she was a missing child."

That's when Deku cried back, determined and low. "Please let me talk to her. I have to know something.."

Not fully understanding, All Might questioned. "Why would you want to do that Young Midoryia?"

Although the boy only dipped his head into a hard bow in response. "Please All Might, I don't think she's as bad as she wants us to think."

Shinso then looked between All Might and the boy before a small bit of hope entered his eyes. Could this mean that his sister wasn't completely gone yet? He wanted that to be the case.

Deku remained in a bow for a couple more minutes before All Might huffed out a sigh, wanting his words to be true as well. "Very well my boy, but be careful. Just because she can't use her quirk doesn't mean she won't try to manipulate you."

Nodding his head, the boy took in the advice before slowly opening the door next to him, the other two watching his every move on what Sienna would do.

When she saw Deku, her eyes lowered in amusement. "Oh would you look at what the cat dragged in, if it isn't the little hero wannabe. To what do I owe the pleasure?"

Shaking slightly, the green haired moved over to the chair next to him before speaking. "Your name is Sienna-chan right? I overheard Kacchan talking about you earlier."

To that, Sienna perked up now hearing Bakugo's name. "So what if it is?"

That's when Deku pushed further. "I have something I want to ask you Sienna-chan, it's about the USJ fight…"

The girl lazily turned her head at his words, not really knowing where he was getting at, that's when he spoke again. "How did you end up captured by the heros?"

Still not understanding, Sienna frowned. "Because I fucked up, that's why. Do you have a point to your constant rambling or are you just bored?"

Although Deku shook his head at that, leaning closer to her. "That's not it Sienna-chan. I saw what you did for Kacchan back there, you just don't want anyone to know, do you?"

At that, Sienna froze, a bead to sweat appearing on her forehead. "I don't know what you're talking about."

But the boy only pushed further, his eyes boring into her for some sort of reaction. "You pushed him out of the way of that Nomu, didn't you?"

Sienna's eyes widened at his words, cursing internally before letting them fall back in a bored position, covering up her own anxiety. "Wow, you are really stupid aren't you? Why in the hell would I risk my own life for a wannabe hero? Sure, Katsuki was fun to play around with but he didn't mean anything to me…"

Yet somehow the boy didn't believe her, seeing the reaction for himself. There was no way Kacchan would have avoided that attack unless someone pushed him out of the way. She was lying for some reason. "Then why haven't you been caught before today? All Might told me that you've never made a mistake until now. So why now Sienna-chan? There has to be a reason for it.."

That's what made Sienna's face fall, shock over her features. Shit, that boy was too good at figuring out her actions. If only her brain wasn't so hung up on that blonde, then maybe she wouldn't have done something so stupid. But it's not like she would ever let him know that.

Sighing in frustration, the girl huffed back. "I just got unlucky, broccoli boy. It happens. I don't know what you're assuming in that stupid head of yours but Bakugo Katsuki means nothing to me."

Deku stared at the girl for a couple more moments before All Might called back to him, now speaking from the back of the room so only the two boys could hear. "It's my fault that she gave up hope, isn't it? If only there was a way to have her relive her old desires of being a hero. Then I'm sure Young Sienna would change her ways."

Nodding his head, the green haired boy sighed. "I think she's lying All Might. I really believe that she saved Kacchan that time. She just doesn't want to admit it for some reason. That means she can't be all bad, right?"

That's when All Might got a crazy idea, now pulling out his phone and dialing a few numbers. Yes that was it, maybe they could go back and fix her ways, to reform her back into a hero like before. "Young Midoryia, you just gave me an idea. I must go speak with principal Nezu immediately."

The two then turned back to Sienna who just looked dumbfounded, not knowing exactly what they were planning. "What, why are you all staring at me like that?"

Lots of stuff here, so Sienna is Shinso's older sister (by one year) and that's why they have similar quirks. While Shinso's is brainwashing, Sienna's is more of an alluring siren song, kinda like brainwashing but using a melody instead of words.

All Might feels majorly bad about presuming Sienna died when she went missing so instead of just locking her away, the man is dead set on helping instead, whether she likes it or not.

Next Chapter: Sienna is forced into All Might's plan of changing her back into a hero as Katsuki and her talk for the first time since their fight.