Hey everyone.

I've been away for a good few months but I'm slowly but surely updating my stories. It took a while to get around to ES, in part because FtS had a whopping 15k word chapter, but a lot of it had to do with me needing to get my head back into this one after so long.

Gosh, has it ever been a long time lol. Emiya-sensei? suffers from long update times more than my other stories, I think. It has a very "weekly" pace but the actual update times are anything but. The fic's traffic problems as its engagement slowly dwindles to nothingness is largely my own fault for this reason.

I was very surprised when y'all on the discord voted for this to be updated. If you want to have a say on what I work on next, please do join. It's open to everyone and there's always an active link in my profile. The more people vote, the more I know what I should or should not put my effort into.

As always, to you all on p atreon, thank you for your support and voting for this chapter's illustration.

X

X

"Lady Nagant! Good job. The villains were apprehended without issue."

Tsutsumi Kaina shrugged off the police officer's praise with a scoff. She removed her visor and passed the support item to her intern, who grumbled at being made into a pack mule.

"Of course they were," she told him, smiling. "All Might was on the job. We were just out here to make sure that there would be no loose ends."

The officer patted her on the shoulder.

"There's no need to be so humble. You're the only one who can do what you do. Just between you and me… you do a great job of keeping the other heroes in check. Who knows what would happen to the hero industry without you!"

Her smile thinned. She looked distinctly uncomfortable but her experience helped her hide it.

"We'll get going now. C'mon, Kiddo."

Emiya Shirou clicked his tongue but knew that now wasn't the time to start an argument. She was self-aware enough to know that she had fun embarrassing him every now and again.

The woman waved to the officer as a parting platitude. She put a hand on the kid's back to direct him in the opposite direction as one would do with a small child. Of course, he slapped the appendage away.

A short chuckle escaped her.

The pair opted to walk back to her agency instead of taking a car. Rather, she did. A walk would help her clear her head right now.

It was a nice evening. Few people were out on the streets in the area given the commotion that had just taken place. It was just her and her provisional, soon-to-be full-time sidekick.

"...Hey. You okay?" the kid asked her.

She offered a non-committal hum.

"Do I seem not-okay to you?"

"Yeah. You've been off for a while now."

"It's been a busy week," was her excuse.

"Longer."

She huffed.

"You used to do a better job of minding your own business."

Keeping pace, he shuffled back and forth awkwardly.

"...It's not always a good idea to do that, I think."

A grin slid across her face despite herself.

They kept walking in silence for a little while longer.

"Hey. Kiddo."

"Stop calling me that. I'm turning eighteen soon."

"If I turned out to be a really crappy person, would you forgive me?"

He stared at her like she grew a second head.

"What are you talking about?"

She moved to ruffle his hair, but he ducked. He was ten years too young to evade a pro hero like her, though. She still managed to plop her hand down on his head and push it down.

"Would you quit it already?" he groaned, pulling away.

She laughed.

"Just answer the question."

"Of course I wouldn't," he grumbled.

She blinked owlishly.

"Oh?"

"If I found out you were a bad person… I'd get mad, I think? I'd make you stop being bad. Definitely."

Her expression didn't change for a moment, then she went right back to laughing her butt off. She pulled him into a sideward hug faster than he could react.

"Hey!" was all that he managed to get out. He blushed but barely fought against it.

"I knew it! Only a kid could give such a childish answer. What does that even mean?"

"Hey! Stupid questions get stupid answers. What did you want me to say?"

Her eyes twinkled. Whether it was mirthful, mocking or something else, he couldn't tell.

"No, no. That answer works just fine."

X

X

Once Archer exited the vehicle, Arthur was there to greet him with a pat on the shoulder and a nod. The blonde was dressed for the job: his everyday wear was replaced by a radiant, modernized approximation of a knight's suit of armour. The look was even tied together with a strange-looking sword at his hip and an ornate blue capelet thrown over his shoulders.

"Shirou! …Miruko-san. You two were able to make it here quickly."

"Mm. There wasn't much traffic on the way. Getting out of the lot at the arena was easier than we thought it would be."

Rumi hopped down from the driver seat of her full-size pickup truck and made her way around. The sheer size of the thing made for an extended silence as they waited for her to reappear from behind the veil of its massive frame.

"...So… what did Stain do?" she asked once she could see the two men. "Archer made it sound like a big deal."

"I would be best equipped to answer that question," a new voice spoke up, its tone sombre. All heads turned to face a plain-looking man with short-cropped black hair.

Rumi held a blank stare.

"...Takeuchi?"

"Tsukauchi," the man corrected tiredly. "This isn't the first time you—never mind that for now. Archer, you aren't going to want to hear this: Stain tried to assassinate Lady Nagant."

The name didn't mean much to Arthur but it seemingly struck a nerve with the other two. The red-haired man's heart stilled.

"What?"

"She was in critical condition when we found her. We rushed her to the hospital, but—"

Archer grabbed the police detective by the shoulders, his body language fervent in a way that was wholly unlike him.

"Is she alive?"

"Yes, but—"

"Take me to her!"

Tsukauchi shook his head and gently removed the man's hands from his person.

"You know I can't do that. She may be a patient, but she's still a high-security prisoner. There are no visitation rights that we can offer you for something like this."

Arthur furrowed his brow, understanding that he was missing context, but no one was willing to offer it to him at that moment.

Miruko's expression was tight.

Archer forced himself to relax.

"...Right."

Tsukauchi patted his arm sympathetically.

"I'm sorry things happened this way. She was on a good track to be transferred out to a healing facility within the next few years, thanks to you. The doctors will do everything in their power to fix this, but right now, it's out of your control. Follow me and I'll show you what you can do."

A pair of masked guards walked up to the group and gestured for them to come through the gates.

X

"It's concerning in the same ways the Black Knight situation was concerning," Tsukauchi explained. "A break-in is different from an escapee, obviously, but it's clear that someone else was involved. I spoke to a few people: security couldn't react in time. None of the defence systems were working properly. If Stain's some sort of tech wiz it's one thing, but chances are…"

"It was a team effort," Miruko finished. She gave Arthur a pointed look; it was obvious she had his "theory" in mind. It was too radical to bring up around a police officer for now, however.

Shirou was only half listening. He stared emptily at the message written in blood across the walls of Lady Nagant's cell.

Are you ready, Archer?

Was it her blood? Probably. He could see it: splatters and droplets near the ruined bed trickling up to the carefully-painted words. It didn't look like the victim put up much of a fight.

"What does Archer have to do with this?" Arthur asked. "This seems awfully roundabout for the Hero Killer. I don't remember any other cases of the man goading a target like this before attacking them. Archer… You know this woman, don't you?"

Shirou didn't turn around.

"Yeah. She's my mentor. Back when I was still in hero school, the plan was to work as her sidekick once I graduated."

Arthur's eyes widened. From the look on Miruko's face, it was clear that he was the only one surprised by this news.

This criminal used to be a hero? If Stain's track record of targeting "corrupt heroes" was to be trusted, then this attack really wasn't all that random.

…Hold on. There was still something missing: why did he go out of his way to target an incarcerated hero? Stain made himself out to be a political warrior. A criminal did not have any "false virtues" for him to target.

"Mister Tsukauchi," Arthur spoke. "What crime did Lady Nagant commit?"

The man's already-dull eyes darkened.

"She had a falling out with a fellow hero. Killed him in cold blood. Supposedly."

Shirou balled his fists. Arthur pretended not to see it.

"Supposedly?"

Tsukauchi hesitated before answering.

"The guy she killed had no previous affiliation with her. If the Safety Commission didn't denounce her publicly, she probably wouldn't even have been a suspect. She refused to deny any allegations in court, though, so the whole thing after that was iffy."

No. That didn't explain anything. His confusion deepened.

Arthur did an excellent job of acting like the mention of the Commission didn't ring any bells. Miruko… not so much.

"That's—!" slipped out of her mouth before she clamped up.

The detective hummed.

"Something wrong, Miruko?"

"It's—"

"I think Stain and whoever was blocking my phone are two different people," Archer proposed out of nowhere, interrupting the train of thought.

Tsukauchi shoved his hands in his pockets.

"...I didn't want to say anything without being sure, but… You're right, I think. This message doesn't look like it has anything to do with someone trying to keep you away, now does it? If anything, it's the opposite."

"So Stain and this other party are working against each other as well," concluded Arthur.

Could it be the Japanese Hero Commission? But… I thought….

He glanced to the side where the two guards stood. They were immobile and unassuming; they were probably asked to make themselves out to be as though they weren't here at all. Nonetheless, they were here, and this wasn't the sort of matter to be discussed in the presence of strangers.

"Is there somewhere we could speak in private?" the foreign hero asked.

Tsukauchi blinked.

"Uhm… yeah. We can all head back to my office."

Miruko stretched her arms over her head and let out an exaggerated yawn. He found it a bit impolite, but he wasn't here to judge the people that were here to help—no matter whether he asked them to or not.

"Let's go, then," she grumbled. Arthur caught the way that she looked at Shirou's back before turning around and walking past the guards.

"..."

It was difficult to tell what Shirou was thinking right now.

X

The elevator ride back up was a quiet one. He wouldn't call it awkward—or actually, maybe it was. It was probably his own fault though.

No one was willing to speak. The guards weren't supposed to, Arthur and Tsukauchi looked like they were deep in thought, and Rumi was… doing something on her phone. The humming of the elevator and the tapping of her fingers were the only noises that could be heard.

Tsukauchi seemingly came back from his own little world for a moment.

"Where were you even keeping that? You're wearing a leotard," he remarked.

She bared her usual toothy smile.

"Wow! I guess you're a pervert, huh?"

He choked on his own spit.

"Wha—that's not what I—"

The elevator door dinged. It opened, allowing the day's fresh breeze to hit them.

"We'll meet there," Arthur spoke over his shoulder. He went on ahead.

Rumi followed suit, not looking up from the screen of her phone.

Tsukauchi offered him a nod.

"We'll get everything sorted. Don't worry."

Shirou could only nod back. Tsukauchi only stood still for a split instant longer before deciding to leave as well.

The red-haired man lingered, trying his best to gather his thoughts before joining Rumi in her truck.

Ah. The guards were waiting for him.

"Sorry," he spoke softly. He put out his hand to stop the door from closing—

His instincts kicked in. He threw himself against the back wall of the elevator a split second before something came shooting up from the ground where he was about to stand. It went all the way through the roof; some part of the elevator mechanism made a strange whirring noise.

Time felt like it slowed down. He held his breath. He could see the others looking back at him wide-eyed, but no one could react in time before the box dropped.

The first thought that came to mind was to protect the two guards from the fall. As high up as they were, there would still only be a few seconds at most for him to act.

Such thoughts came to a grinding halt when he noticed the corpse of one the guards slumped over, blood spilling out from his neck. The other one was standing over him with a knife in hand.

"Tch!"

BAM!

It took Shirou a second to gather his wits once the elevator hit the ground. It was little more than a crumpled mess at this point. He would have been left the same way if he hadn't used Rho Aias at the right moment.

… The attacker was nowhere to be found.

He climbed out of the box and looked around. This floor wasn't familiar to him: there was a long, narrow hallway that didn't seem to lead to anything.

"Where—"

A loud alarm started blaring. Bright red lights were flashing in his face. He flinched.

The whistle of an object cutting through air was barely audible over the noise, but his trained ears caught it. He whipped his head around and barely had the time to crank his neck out of the way of a knife before it sailed past with nothing but a hair width to spare.

"Archer."

The murderer stood before him, his posture relaxed. A hand came up to remove the guard's mask.

The man's face was in ruins. His nose was gone—torn off, seemingly—and wide, bloodshot eyes were covered by scraggly black hair that likely hadn't been washed in a good while. Seeing Shirou's serious expression, the killer's mouth opened wider than what should be possible and a grotesque, spotted tongue rolled out.

It was an approximation of a smile.

"You're Stain, the Hero Killer," Archer remarked. His blood pumped heavily through his veins as his quirk bubbled within him.

The murderer didn't answer. He didn't need to.

"I'm happy you came," he said, a hand pulling long black locks away from his face. "We'll have a bit of time to ourselves: maybe even a good few minutes depending on how difficult they find it to make their way down here."

"I don't know what you're expecting to accomplish here," Archer admitted, his tone even. "After everything you've done… all you've managed to do here is make it easier for me to catch you. You're not getting away."

A dozen floating swords moved like bullets as they aimed to incapacitate the enemy. Without an intent to kill, however, it was child's play for Stain, mobile as he was, to predict and evade the onslaught. The metal of the hallway walls shrieked as the missed shots turned it into a pincushion.

"Are you angry, Emiya Shirou?" Stain asked, his raspy voice sounding almost amused. "For what I did to your fellow heroes? For the people I've killed? For what I did for the greater good?"

"There is no good in what you've done!"

The hero held a small, black cylindrical device in hand. In an instant, it expanded and warped in a flurry of mechanisms until it transformed into a giant black bow, longer than he was tall.

Stain scoffed.

"What do you think you'll be able to do with something like that in—"

He didn't have time to finish his quip. All his effort was put toward hurtling himself out of the way of something that was moving faster than he could comprehend. Even still, the air pressure alone sliced up the side of his leg.

BOOM!

Stain didn't have time to be shocked by the noise made by the impact of that something, nor did he have the time to look back to see what that something even was. Another weapon was notched and Archer looked ready to let it fly at a moment's notice.

"Hey… hey… if you keep that up you might just go too far and drop the whole prison on our heads, you know!"

Despite the words of caution, the Hero Killer's tone was far from cautious. None of the amusement had left him.

"No I won't," Archer rebutted simply. Confidently. "What I'll do is take advantage of the opportunity you've given me to stop you from keeping any more heroes off our streets."

Somehow, Stain's grin grew wider. The obviously-crazy man rushed straight toward him, uncaring of the various blades spearing his legs and arms as he made his way forward.

"Sometimes a hero isn't what's needed for the greater good," he preached, somehow keeping the pain out of his voice. "Sometimes there needs to be a villain. You of all people should know that.

"Right 'Kiddo'?"

…Bizarre. When was the last time that anyone—

Archer's attacks ceased for a moment as what the man said was processed.

"You—"

His expression contorted into one of anger before immediately evening itself out.

"Don't mock her," he snapped.

Operating at the current level wasn't fast enough. Stain wasn't on his level, but he was driven and crazy enough to make things difficult in the current space.

Shirou's eyes hardened as he pushed his quirk a little more.

X

Thump. Thump. Thump.

"What the hell is going on!" Miruko shouted. She kept slamming her heel into the elevator door, which closed as the prison went into total lockdown.

"That's not going to work," Tsukauchi told her. The man had to raise his voice so as to be heard over the sirens. "The doors are meant to stand against even the strongest of strength quirks."

Thump. Thump. Thump.

"And the elevator itself?" Arthur asked.

"...It's a lighter and smaller traction elevator for visitors and staff, not the hydraulic one used to transport criminals. It was a weak point but there shouldn't have been a way for a villain to take advantage of it."

Thump.

Miruko paused mid-stomp.

"Damn it all. Does no one work here?"

Tsukauchi sighed.

"Tartarus is in lockdown. We're cut off from everyone else—and locked out from getting back in—until it's lifted. The technicians are in the same boat. There's nothing that we can do now but wait."

"Fuck that!" she screamed. "Is this really how these Tartarus guys handle emergencies? What a mess!"

Tsukauchi shook his head.

"No. This isn't normal at all. Tartarus doesn't go into lockdown. There's a plan of action. There's a system. The fact that nothing is happening—the fact that none of us can get anywhere—means that the prison is vulnerable."

"This was a trap," Arthur concluded immediately. "Whoever was keeping Archer away obviously knew that the provocation in the cell wasn't the end of it."

Miruko's eyes widened.

"So whoever attacked him just now—"

"That was probably Stain. That's my guess, at least."

Tsukauchi clicked his tongue.

"...Yeah, that scans. Damn it!"

"I'm breaking through the floor."

"My support item is pretty strong but it'll probably do more harm than—what did you just say?"

Miruko ignored them and looked up at the sky.

"Blondie. Can you pack a punch?"

Arthur didn't know where she was going with this.

"I don't have a strength quirk."

"That wasn't what I was askin' ya."

"..."

He sighed and brandished his sword. There was something off about it. As though there was more to it than a regular—if ornate—blade. A humming sound came from it: something that could be most similar to that of wildly spinning gears and wheels.

"It depends. What are you trying to do?"

She grinned.

"I need to get really high. Can you bat me up?"

Tsukauchi looked at the man's sword and paled.

"I don't think it works that way," he remarked.

"I also don't think it works that way," agreed Arthur.

She rolled her eyes and tapped her feet against the pavement below demonstratively. The metal of her armoured foot coverings rang with every strike.

"Oh, shaddap. Just do it!"

She started running at the foreign hero and he quickly realized that she wasn't open to commentary, nor did she care for their criticisms. By the time she took her gather step, he was forced to commit lest he let her crash right into him.

He grit his teeth. This woman didn't understand the concept of working things out as a group.

It's your own fault if this ends badly for you!

He swung up; the momentum was carried by the weapon's internal mechanisms rather than his own strength. Even still, something inside sounded like it was grinding, putting up a fight, as she slammed her feet down on its edge to use it as a springboard.

He didn't know what impressed him more: her leg strength or how well her armoured soles were holding up.

"Strike Air!" he shouted. The voice command released the built-up energy all at once as a stream of pressurized air.

Tsukauchi had to cover his face as the excess wind blew outward. The combined power of the support tool and Miruko's legs had her rocketing a hundred metres into the air.

The two men shielded their eyes and cranked their necks. Her figure was tiny at this distance and the sun didn't make it any easier to see her.

"What do you think she's—"

"Luna Fall!"

X

X

13th of February, 10 Years ago: outside the courtroom following the sentencing of former professional hero, Tsutsumi Kaina, convicted of the second-degree murder of a fellow hero.

Shirou leaned against the wall, not trusting his legs to support his weight. His eyes stared ahead emptily, not that there was much to see in the halls. He was the only one here.

He couldn't go in.

He had rushed here from school; his uniform was dishevelled. It would be unsightly for him to be present looking so unkempt.

That was the excuse that he kept giving himself.

He was jittery. His hands were normally much steadier. Never had he felt so turned upside down.

The shaking spread to his knees; he slid down the wall and sat on the ground.

She didn't do it.

She didn't do it.

She didn't do it.

There was no way. This was all just a strange mistake, right? His mentor has good lawyers. They'd get it all sorted.

Any time now. They'd all walk out and tell him what he already knew.

That time came.

He clumsily got back onto his feet and kept his eyes locked on the crowd of people exiting the courtroom.

He heard what they were saying. What they were saying about him.

"Is that…?"

"Does he know the verdict?"

"I doubt it. He couldn't bring himself to watch."

"Awful."

"Do you think he knew about…?"

"No. They brought him in for questioning. The wool was pulled right over his eyes."

"Poor kid."

He heard what they were saying about her.

"What an awful woman."

"I can't believe she was allowed to act as a hero for as long as she did! I doubt this was the first time that she got out of hand."

"How petty and small-minded do you have to be to kill your fellow man like that?"

"At least she knew that she screwed up. She didn't even try to plead innocent."

He took off in a mad sprint without thinking, pushing through the crowd with all his might. As a hero in training, quite a few people were knocked onto the ground by his strength. Though he would have normally been conscientious enough to help them up—or not do that at all, rather—he couldn't think about anything else at that moment.

He burst into the courtroom, catching the eyes of many onlookers as he was the only one rushing in as everyone else was leaving. He paid them no mind.

There she was.

She hadn't been taken away yet. A group of officers and guards were huddled around her about to do just that.

"Sensei!"

At his calling, her head jolted up. They crossed gazes.

She didn't look right. This wasn't what his mentor was supposed to look like at all. This was the first time that he had seen her face-to-face in weeks. Not since she was arrested.

Her expression was that of a deer caught in a car's headlights instead of overwhelming confidence. Her long and wild mane of hair was reduced to a knotted and shaggy mess.

"Shirou…?"

Even her voice was—!

The guards tried to stop him, but they couldn't. In a split instant, he was past them and grabbing the shocked woman by the collar of her orange prisoner's jumpsuit.

"Tell me it's a lie! You didn't! It's not possible! I know you!"

His eyes were teary. His frustrations built up the longer she remained silent. The guards got a hold of him and tried to drag him away but he held on strong.

"This is a bad look, kid," one of them hissed. "I know you're upset, but think of your own future! This isn't how a pro handles situations like this."

…A pro?

Who the hell cares about that right now!?

Without looking his way, Shirou bucked his shoulder and threw him off.

"Sensei… Sensei! Tell me why! There was a reason, right? What aren't you telling us!"

A pair of cuffed hands rose to caress him gently on each cheek.

Her eyes were teary. Tired.

But she was smiling at him. If it weren't for the tears, he would have sworn that smile was as bright and reassuring as ever.

The guards finally got themselves together. They tackled the boy to the ground and held him there while others pulled the prisoner away.

"Shirou!"

He craned his head up desperately. That smile was still there.

Why was she still smiling?

"You'll do just fine; you don't need someone like me around to drag you down. I know you'll be a great hero, Kiddo."

X

X

Present day: undercroft of Tartarus.

The Hero Killer, Stain, had been bested in combat.

Impossibly enough, a dozen swords pinned him to a solid metal wall. More than half of them pierced straight through his body.

The villain coughed; dark blood dripped down his chin. His ribcage was beaten to a pulp.

Shirou stared at the man impassively.

"I really wanted to know… if you knew anything," Stain wheezed out. "I guess she left you in the dark. It makes sense."

"What are you talking about?" Shirou bit back.

"You know what I'm talking about, Archer. You're not an idiot."

The hero made a complicated expression.

"You're acting like you know something that I don't."

"I know that you visit her every month," Stain drawled, his voice wet. "I know that you try to get her to speak. You try to get her to give you any excuse, any reasoning that would help her get her sentencing reduced. It won't work, though. She won't tell you anything and they will never let her out. Too dangerous.

"Even now, you wonder why it is that she's never been honest with you."

Shirou couldn't let any emotions shine through. Not now.

"I'll ask you again, Stain: what do you want?"

His laughter was interrupted by a short-lived coughing fit.

"You already gave me what I wanted. You're what I wanted. As a hero, you're truly spectacular, Archer."

The red-haired man grit his teeth. Stain wouldn't talk sense.

There was nothing more that he could do here. He wasn't any good at interrogations; it would be best to bring him to the police.

He opened his mouth, but Stain continued before he could say anything.

"This was… the correct decision! Lady Nagant is right to be proud of you, just as your father would have been. This was… all that I could do."

Shirou's heart stilled.

"Just now, you—"

CRASH!

A portion of the ceiling caved in. Shirou's instincts caved in and he used his quirk to conjure something to protect his and the villain's heads.

The debris kicked up a cloud of smoke. It took a moment to clear out.

"We caught ya!" a very distinct voice shouted.

Miruko stood in a rubble pile of her own creation. She poked her chest.

"We're here to—" the woman noticed the incapacitated villain. "Oh."