Story is AU.

Chapter 1 - A Hero for a Hobby!?

The skyline of Downtown Fuyuki was brightly lit and shone in contrast to the cloudy night sky. Despite being so late, streets were still crowded with people, which either consists of young blood excited for night life or tired white-collars heading straight to home. Traffic, just as always, never seemed to change. All in all, Fuyuki was still lively even at this time.

Which means that she has to be careful; there were too many witnesses. All they had to do was to look up and…

A cloaked figure jumped from building to building with incredibly lengthy leaps. It was an impressive display of mana control on using reinforcement. Tohsaka Rin clicked her tongue as she observed the magus from afar.

While she could do it, she can still mess it up and potentially hurt herself—a fall from this height would definitely be fatal.

And of course, that upstart rogue magus knew that.

She grit her teeth. "I've been tracking you for a while now… like hell I'll let something like this stop me!"

She took a deep breath.


She imagined her mental trigger inside her head. A stab to the heart; a very gruesome image to be pictured but the familiar shock is enough to activate the magical circuits inside her. In practiced form, she redirected the flow of her Od to her legs, cracking the stone on her feet as she launched herself towards the rogue magus.

She took out the jewels in her pocket as she neared. The cloaked magus inclined their head minutely to look at her.

"Gandr!" She tossed the curses.

The potent magical gandr curses homed to the magus, leaving a sparkling trail on its wake. The cloaked magus, in response, turned around in an unhurried manner, bandaged covered hand reached into their cloak.

"Invers." a cold voice under the cloak stated.

The magus tossed something that Rin didn't see, and the homing curses that closed in on the magus exploded prematurely, only leaving a blast of wind pressure that made the magus' cloak flutter against it.

The two of them land on another building's roof.

"A-A counter curse!?" she said in shock as she looked at the smoky remains of her magically empowered jewels. She spent days storing mana in those!

"Such a naive girl. It's surprising that a magus of your level was given the title of Second Owner, but I suppose that it's expected for a backwater place such as this." said the magus.

The insult snapped her out of her shock and made her grit her teeth, but she reigned her anger in. "'Backwater', you say? Then what of you, scuttling on this 'backwater' like a rat in a sewer?" she coldly replied.

She felt the gaze of the magus under their cloak boring straight at her.

She furrowed her brows. Did she say something wrong?

"...What?" she growled out, fed up with the silence.

The magus shook their head as if disappointed.

"Hm. An enemy of the Mage Association I may be, but I am no fool that does not tread lightly."

Tread lightly...?

This is new information. The rogue magus right in front of her was once a Mage Association's enforcer with a body count nearing triple digits. They had an incredible amount of history in violence, so for something to make them "tread lightly"... she needed to know more.

The magus seemed to think of her as naive and ignorant. Better play on that.

"...What do you mean?" she said, as if impatient.

The magus scoffed.

"It simply means this: your horrible management made this place quite dangerous." the cloak shifted. "But this is no time for chat. Your efforts of chasing me proved amusing, but I have places to be."

Still facing her, the magus jumped backwards, floating above a large gap between two buildings and no doubt planning to escape once again.

"Wait! Tch." she brought out jewels in her pockets again. "Gan–!"


She yelped and tossed the jewels to the side before the counter curses could blow the gandr curse along with her hands. She involuntarily covered herself from the blast.

When she recovered, she had opened her eyes to dissipating smoke, with the magus nowhere to be found. Feeling a sense of panic she immediately ran to the edge of the roof and searched for any possible place that they went.

They're gone…

She pulled her hair in frustration. "Ahh, dammit! Now I won't get any sleep! Urgghh, this is so stressful!" she shouted. "Stupid, upstart, magus, who the hell do they think they are!? Stop talking like you're cool—your cloaked outfit looks lame! What are you, some sort of chuunibyou!?"

Tohsaka Rin took a few deep breaths, then slowly stood straight back up again. Calming herself down, she began to review of the possible places where they could be. They couldn't have travelled that far.

"I swear, once I get my hands on that magus, the bounty better be worth it!" she whispered harshly under her breath as she turned around and ran.

And so, the Tohsaka searched for the magus once more.

As the Tohsaka heir left, the magus simply watched as the naive girl passed by their position, covered by their invisibility Mystic code that was grafted on their coat.

"Disappointing. A competent magus would at least have learned one or two scouring spells up their sleeve... this city truly has the worst enacting authority I have ever witnessed. No wonder this place has gone into chaos." the magus muttered.

The magus dropped down into the gap between two buildings, landing softly on the ground of an alleyway. They walked opposite the direction of the main roads and brightly lit streets, and instead went deeper into the darkness.

The grating urban noise of people chattering and cars blaring their horns behind the magus slowly begin to fade away, only to be replaced by an unnaturally tense silence—something that the magus had noticed even in his short time ever since arriving here. The city seemed to hide something dark within it if one were to look carefully.

Fuyuki City is a mysterious place. On the surface, it was fairly innocuous and barely worth any attention, but dig a little deeper and it will reveal its history to be a fascinating and bloody one. The area itself was built atop a ley line—any with the ability to feel magical energy would immediately feel the difference of the density of mana present in the air when they set foot in this place.

Naturally, the place was abundant in supernatural things. It wouldn't surprise him if he wasn't the only one to be interested in a place such as this. With the fact that the Second Owner seemed to lack any sort of capability, everything here was free reign—so long as you didn't step on anyone's toes.

It was a perfect place to enact the magus' plan.

"Just a few souls more… Once I manage to extract a few more human souls, I can finally see where the souls can go when they inevitably return to the Akashic Records. And this place is exactly the power battery I needed to do so." the magus chuckled darkly. "Once they hear that I managed to peer through the Root of all things, those fools in Clocktower would finally see the greatness of my work!"

Now, they just needed to lay low and continue the extraction. A few hundred souls of civilians is what they need, something others would define as numerous, but perfectly within capability of the magus. They'd have to be careful if they didn't want to attract the attention of anyone powerful, though. Abductions happen all the time, but a large amount in a short span of time would cause suspicion.

They'd have to pick their targets carefully. It would be ideal that they'd get a hundred souls from a hundred people which no one would bother checking, but it was unlikely. Perhaps if they stretched out the time of kidnappings to make them unrelated...?

The magus emerges from the alleyway and into a poorly lit street. There was no one around, and the place was completely quiet, save for one jogger that was a short distance away from the magus.

"...Speak of the devil. I suppose I should start already." the magus said, looking at the jogger. "A chop to the neck should suffice." they stated clinically.

A short burst of movement, and the magus was directly behind the jogger, holding a hand up high. The jogger didn't even notice the incoming guillotine that would end his life.


The hand was brought down–

–which then met something hard, followed by an intense stabbing pain.

The magus, behind their cloak-covered face, looked at their broken hand on the jogger's shoulder with wide eyes.

I-Impossible! Their reinforced limbs can cleave through metal that are inches thick!


Reflexes in action, the magus immediately put some distance between them and the jogger. They cradled their broken hand with one arm and inspected the damage. Broken bones, especially in the metacarpal part of the little finger. Nothing a healing spell wouldn't fix, but it was already unusable in the fight. Not unless they wanted permanent damage.

The jogger turned around to fully face the magus.

"...Hey, did you hit me just now?"

The jogger's body language is perfectly relaxed. He didn't feel any sort of pain from the attack. In fact… he might have never noticed it. The magus involuntarily swallowed as they felt their throat had gone dry.

Just what had they managed to encounter here? Is it even human?

Activating a perception acceleration spell, the magus considered the situation. They were in an abandoned street. It was only the magus and the enemy in front of them. It is possible that they might not be facing only one, but the lack of any magical signatures nearby makes it not likely.

Their intuition in all their years of being an enforcer were screaming. The… thing in front of them was dangerous, extremely so. In all of their years in fighting, they had never felt something like this. Should they try to escape? No, they had a feeling they wouldn't be able to outrun him. Running would only present a vulnerability and split their focus in escaping and dodging any attacks.

Which means, there is only one way they could survive this…!

The magus brought out their most powerful mystic code out of their cloak. A bright red light illuminated the dark street as mana flowed from the magus to the mystic code. A high-pitched whirring noise rang malevolently.

The magus pointed the mystic code to the jogger.

"Spulbera!" Disintegrate!

The mystic code, a high-energy and unstable projectile that would overload anything it passes with kinetic energy, causing its constituent particles to scatter and make the object disintegrate, was thrown and immediately launched at high speeds in a straight line. The ground cracked from the sudden displacement of air pressure as the projectile was launched, ruffling their cloak.

The magus could see it. The projectile went near to the jogger, a distortion of vacuum left on its wake and…

An explosion of pure magical energy. The ground trembled, and the surrounding buildings' walls cracked and window panes shattered into pieces. Concrete scattered everywhere and a cloud of dust blew up, reducing the visibility of his immediate surroundings.


"D-Did I do it…?" the magus muttered as he stared at the smoky aftermath of his spell.

"Don't attack people out of nowhere." a voice scolded behind him.


The last thing that the magus can see after abruptly turning around was a blur and a nearing fist on his face.

"–I'm telling you, I need the information right now! ...No, I didn't let them get away, it's just that their mystic codes are—I told you, it's not like that!" Tohsaka shouted at her phone as she walked on the street, making other people's heads turn to her. She ducked a bit under embarrassment.

"Look, just tell me if you find something. At least by then I'll be out of your hair this time." the young woman remained silent for a bit as she listened to the other side of the line. "Yeah, yeah... Okay. Fine, it'll be the same price. That's fine. Alright, bye."

She brought down her phone, then squinted her eyes as she tried to remember how to end the call again. It's… that red button right? She pressed it, and thankfully it was the right one. At least she didn't embarrass herself again.

She sighed, pocketing her phone. Technology… why is it so hard to use? So many buttons, so many things that she has to know... this is why she wants to just stick on her magecraft to talk to other people from far away.

Before she could give out a mental rant on how society was leaning to where she would be using machines all the time, she stopped as she saw something in the distance. A group of about ten or so people were crowding on some street. She could see that the police were involved.

She furrowed her brows. Could it be…?

Hurriedly walking towards it, she pushed through the small crowd.

Immediately she saw what was going on.

Broken concrete all over the place. There were so many cracks on the walls and pavements that it looked like a bomb had gone off. But, what had she recognized the most was a familiar cloak.

The magus she was chasing earlier, which was known for the destructive power of their spells and had a notorious reputation for being a dangerous foe in combat, was buried comically under the pavement with their ass up high.

Rin would've wanted to laugh, but she only let out an aggrieved sigh.

"Not again…"

This wasn't the only time it had happened. Her finding about a dangerous thing in Fuyuki, going ahead to track it down, and when she finally did, she would sometimes find them buried under rubble completely defeated by… something.

Just what is causing all this? She had some theories, ranging from an underground organization to a supernatural monster, but she never had any clue on what it could possibly be. The magus seems to have an idea on what it was, which was why she tried to fish out some information earlier.

For now, she has to call the Association and alert them on the development. And also deal with all the people that witnessed everything here. She has to use hypnosis to wipe out their memories, replace it with fake ones, and work on making it look like there are no contradictions.

She looked at the officers on the site with bleary eyes. No doubt that they already had records of this... she'll have to deal with that too.

She rubbed her forehead. "So much work to do…and it's the start of another school year next week as well..."

Flaring her magical circuits, she began to form a boundary spell that would make everyone avoid the area around them. After that, she'll go with her hypnosis.

Despite being a bit irritated about what she has to do to deal with the aftermath of the situation, she can't help but be anxious about how things are coming along. What sort of thing is hiding in the city? It only seemed to target rogue magi and criminals in the past few months, but what if it was just a coincidence? Worse, what if it was already attacking innocents?

She hoped that she could at least… No, she could do something about it. She was the heir of the Tohsaka family; Her father raised her right, and she would be protecting this city to live up to their family's name. It wouldn't do good for her to think that way.

She should make plans. She's been neglecting it for so long, choosing to find threats which she was sure that exists, but now with some confirmation of the magus she can at least act on it.

She hoped that whatever it was, it wouldn't be a pain to deal with.

But for now, Tohsaka will continue with her work, just like always.

Far away from the Tohsaka, the "dangerous thing" that she was worrying about is currently jogging their way in the street. It was already late, and intent to not get into any sort of trouble, the jogger had opted to return home.

Stopping at his destination, a large Japanese mansion in the residential district of Fuyuki, the jogger used his keys to unlock the sliding door and went inside. He deposited his shoes near the entrance and walked towards the living room.

"I'm home!" he called out.

"Hurry up and cook already! I'm hungryyy!" a woman's voice immediately replied back.

The jogger's eyebrow twitched as he removed his tracksuit and changed into a t-shirt. Entering the living room, he saw a pony-tailed woman sprawled on the floor as she watched some soap opera on the TV. He looked at her with deadpan eyes.

"You sure do look busy. If you're so hungry then cook it yourself."

"Kids like you wouldn't know what it feels like to work as an adult." the woman said without removing her gaze from the TV. "The moment when work ends, the only energy you can spare is to dream that someone will be giving you a warm bath and freshly cooked dinner once you get home."

"That's why you're still not married, woman. Your standards are too high." he said, walking towards the fridge. Checking the things inside he saw... chicken and a couple of vegetables. Should he go for a Stir fry?

"Oi! Isn't that too much!? Do you really have to say that!?" she cried out, finally standing up.

He didn't give her an answer, instead choosing to go to the kitchen and turning on the stove.

"...Hey, why do you jog so late anyway? You're not doing anything bad while you're away, are you?" the woman asked, his earlier offense to her seemed to have been forgotten. Fujimura Taiga, his guardian and his sister all but by blood, leaned on the kitchen cupboard separating the kitchen to the living room. "Saitama... are you listening? Apparently it's getting dangerous recently."

Saitama inclined his head to her, before turning back to his cooking. "Ah, well…"

His mind went towards the amount of weirdos that he encounters whenever he goes outside. Just the other day he saw a huge wolfman that looked like it came out of a horror movie. Now, he saw some weirdo wearing a cloak like he's some sort of cosplayer throwing bombs at him.

Just like he always does, he punched them straight—which is pretty much what they deserve for attacking people out of nowhere. He never expected becoming a hero would mean that he'd encounter weirdos from time to time, but he supposed he shouldn't be surprised. He certainly did enjoy the fights though, even if the pain bites his ass later.

So there's only one way to answer his sister's question.

He scratched his hair. "...I guess it's something of a hobby."

He was a hero for a hobby. Becoming a hero in this age isn't really practical and doesn't exist as a career choice, but at least that way he can still do what he enjoys. It's a bit embarrassing to share his hobby to others though.

"Here, dinner's ready."

"Oh? That smells good... but is it tasty?"

"It better be. So are you going to eat it or not? I'm gonna eat it all if you don't."

"Hehe, I'll be good. Thank you for the food!"

"...Thank you for the food."

And so, Emiya Saitama ate dinner with his elder sister, Fujimura Taiga, while watching the news on TV. He chewed his food, occasionally nodding his head to whatever his sister said but never really listening.

"Ah!" he stood up suddenly.

Taiga jumped. "Huh!? What's wrong!?"

"I forgot that there was a sale in the supermarket today!"

"...Nobody cares about that, you moron! Don't surprise me like that!"

I remember doing a Doom and LoZ crossover sometime ago, and my lack of plot-making skills immediately hit me with a roadblock. I hope this time with this story, it'll be different.