A co-op story by Hello-Dark and Just-Your-Averge-Barserker we do not own FGO or High School DXD they belong to TYPE-MOON and Ichiei Ishibumi. Read to the end for the A/N's

A train station in a town near Kuoh city.

The radiant sun dipped below the horizon as the train glided into the station. Stepping onto the platform, a youthful man emerged. Despite being away for two and a half years, he hadn't aged a day. His messy black hair billowed in the wind, and his piercing blue eyes scanned the surroundings. Doubt lingered in his mind about his family's presence. He hadn't kept in touch with them, particularly his not-so-close relationship with his mother, and he had no idea about the whereabouts of his sister, Gudako. Stepping into the bustling city from the station, he meticulously scrutinized the streets and sighed upon realizing he was alone, save for his fellow passengers. However, a small black SUV caught his attention, and he noticed a man standing beside it, holding a sign indicating he was there for the young man. The man was tall and slim with a short stubbled beard, wore a suit, and was obviously from the Association or was at least in touch with Chaldea.

"Hey, are you the boy Ritsuka Fujimaru?" the man asked as he noticed the boy, who lifted a hand in reply.

"Yeah, that's me, and just call me Ritsuka, it's not like I'm anyone special," Ritsuka spoke as he came up to the car. The taller man frowned as he turned and opened the passenger seat door for him, and spoke again.

"What do you mean didn't you save the whole damn world from incineration?" it was not the mockery that came from this man's mouth but the first real question he had heard in a long time and it made the young man smile slightly as he put his little bit of luggage in the back and found his way to the passenger seat.

"I guess, but the bigwigs don't seem to think so, well anyway where is this car headed?" Ritsuka laid his head against the headrest gave an audible sigh and fiddled with the trinket that Da Vinci had given him "If you are ever in trouble smear some of your blood on this and it will help you" is what she said.

"Well I believe you did; and did no one tell you were going to Kuoh City someone with lots of power got you transferred into Kuoh Academy since it's gone co-ed this year." the man said as he stepped around to the driver's seat

Meanwhile at Kuoh, in the Academy Student Council room.

She sat at her desk as she went over all her transfer forms and other forms, she shifted her glasses on her face as the face of the only late transfer of this year glancing one more time at the young man's record and there she frowned as the sheet was completely blank for the past two and a half years and the past before that he had completely average scores on his tests.

"Tsubaki will do a little digging on this boy Ritsuka Fujimaru for me I need information on why he has been gone two years" Sona the student council president spoke as she handed the paperwork to a girl with long black hair, She nodded as she took the papers.

"Yes ma'am I'll see that it's done." she turned to leave the room. Still, suddenly the council president and her assistant felt a ripple in the magic around the city's outskirts as an unusual signature of strong energy rising. Causing the council president to frown as she turned and walked to the window and looked off in the direction of the disturbance trying to see where the surge of energy came from.

Occult research club

She felt it and so did her queen, she also had no doubt her best friend did too it was minuscule compared to theirs but it was there, an unknown magic signature had dared enter her domain and, while she knew her friend would be worried about it Rias couldn't help but feel something was about to go down. Rias turns to her friend and asks if they felt the energy too and they all nod Rias's face goes Blank as she realizes that it is not too far from where they are located inside the old school house.

Kuoh City, Chaldea safe house Site: Saber.

"why a safe house?" Ritsuka spoke as he stepped out of the car and into the bounded field that deterred any normal Human with Rank C magic resistance or lower which meant that you had to be either a Lord of the Clocktower, Saber class, or higher Servant to even see the place, to most people it would look like an empty plot of land, or whatever their brains came up with to fill the void in the fabric of reality, in fact the only reason Ritsuka could see it was the Command Spells that still hadn't vanished yet.

"There seems to be a lot of individuals with unsavory lifestyles and also it seems that the same person who got you sent here, wanted some safety measures put in place." the man spoke as he grabbed at the keys and went to unlock the door and as he did Ritsuka got a twinge in the back of his neck the kind he got thousands of times when he was in the heat of battle. He was being watched they were good at hiding but they were nothing compared to Hassan or any other of the Assassin classes, Ritsuka looked back in the direction of his feeling and got a glimpse of someone moving in the shadows of the trees they realized he noticed. "Is something wrong ritsuka?" the man said as he popped open the door to the small house and waved a hand for Ritsuka to enter.

"No, just thought I was being watched, that's all." the young man said his head turning back to the taller man as they entered the building. It was a small house it being only e living room a kitchen and a bedroom but it was decked out in everything one would need for living including a TV and every gaming system one could want.

"Is that so, well I hope you were not right the top brass would have my head." the man scratched the back of his head.

"Yeah, I guess you'd be right about that." At this point, he knew full well how the clocktower did things, anything that could in any way endanger their seat of power POW, was erased just like that, the only reason he hadn't mysteriously disappeared was they'd have a literal army of servants after them, and An angry Berseker charging you could be the most terror-inducing thing especially when that Berseker was an ancient Greek demigod, and frankly he was surprised they allowed him to leave and didn't take his command spells not that he'd need them as a civilian.

In the trees at the safe house.

The shadow clamped down on her thumb. This was not good. A new mage had arrived in the city, so she decided to sneak up on him and kill him. But there was a problem. It seemed that the boy had been taken under the wing of a fairly skilled mage that she couldn't feel before, judging by his mana. While the boy himself was not very proficient, he had the potential to become powerful if the devils chose to recruit him. The second problem was that he noticed her. How did a weakling like him manage to notice her? Two black tethered wings shot from her exposed back as she took flight and launched off in the direction of the old church.

School gates the next day.

Ritsuka Fujimaru hesitated as he entered the school, his heart started beating at an alarming rate, he may suck at sensing the supernatural but he bet any three-bit Mage could at least from Chaldea could tell there was a barrier around the whole school and he knew his unique Mystic Code that he used to covet his Command seals would not go unnoticed, he choked down spit as he stepped across the barrier.

Old schoolhouse same time.

"Sona, I'll send my Akano to look for the source," Rias spoke managing to keep her temper in check while her friend looked as impassive as always though Rias could see the slightest hint of a frown on Sona's lips, it felt like an enemy had just strolled through the barrier it had no ill will like the person didn't even know there was some here who they opposed.

Back with Ritsuka

There were two things that he noticed as he made his way to the teacher's faculty office one was the massive amount of women which wasn't exactly unexpected this was an all-girl school originally the second was the three boys sneaking out of the girls' bathrooms one was a boy with a shaved head and squinting eyes another was a boy black hair and reflective glasses the last one was a boy with brown shoulder length brown hair and light brown eyes.

"If you gonna sneak in and out of places you're not supposed to be then learn at least presents concealment first, not that you'd know what that is," Ritsuka said as he shifted the bag at his side and watched as the three boys' heads moved like the automatons from the London singularity.

The three boys' plan was perfect they waited for the perfect time, got in, and got out but this black-haired bastard had to show up and ruin it.

"Who the hell are you?" the bald boy yelled pointing an accusatory finger at Ritsuka who moved the finger to the side with two fingers.

"It might be more beneficial for your attention to be directed towards the group of girls in the hall behind you," Ritsuka suggested as he pointed at the girls behind the three. Among them was a short-haired girl who cought his attention, with her cat-shaped hairpins, and hair color that Ritsuka found familiar from his experiences with several servants in Chaldea. However, it wasn't normal in Japan. But her unusual hair color wasn't what cought his attention, it was her angry, almost uncomfortable look she was giving him that specifically cought his attention, a frown crept up onto the former master's face as the girl turned and grabbed one of the boys one with brown hair, and dragged him off. Something felt wrong but the man who saved mankind couldn't figure out what, first learning that the place had a lot of mages than the bounded field and now that girl tense actions just now, and it worried him.

With Akeno.

She asked the rook to help find the source of the unease in the city and the school grounds. Akeno quickly narrowed it down to two possibilities. First, it was a young man named Ritsuka Fujimaru, a late transfer student in his last year, Second was the boy her king had her eye on but the latter was unlikely cause he had entered many times before and this reaction had never been felt. So She sent the rook to the first since he was the more likely of the two options and so she could possibly figure out his reason for coming here. However, the white-haired girl returned to the old schoolhouse without ascertaining his reason but, still with some important news about the boy, The boy had a smell of foreign magic to the Rook, or at least a single spell, but as far as the Rook could tell, it was a completely unknown, and was not good to have mage come there unannounced specifically when the devils domin they were in was of the Grimory and Sitri's.

Arctic Circle, Chaldea security organization.

There were three things the painter/inventor had left to do before packing up the rest and returning to the throne of heroes one of which was handing the pocket instrument she had created to monitor the vitals of the savior of mankind over to Mash. the last master of mankind would never be allowed to return to Chaldea and Mash would never again see the man who rescued her from the despair, the girl was in but this was the least Da Vinci could do. The device served two purposes one was to make sure Ritsuka Fujimaru was safe the other was to initiate the forced summon of heroic spirits protical she inbeaded with in the tool using mash as a conduit for it, if Ritsuka's vitals were to fall to lethal levels or he dropped some of his blood onto the the small trinket, she'd given to him. and the second one was, to give Mash some hope for the future.

"Are you done, Da Vinci if you are I'd like to have a word with you." The detective said lighting his pipe and letting out a puff of smoke the man had an extremely thought-filled look on his face as he took another puff.

"Sure what is it, Holmes?" Da Vinci asked as she stuffed the device into one of the pockets she made in her dress, and picked up the staff she had with her.

"You see Da Vinci something has been bothering me ever since we sent the boy back to Japan." he puffed again on the pipe. "It seems strange the Clock Tower would just let the boy go without a second thought." he put his free hand to his chin. "Now this is just a hypothesis and normally I would never voice my thoughts without proof of my claims but, I think we are getting played for the fool and someone is behind his quick release and the place in which he was sent." he took a second and studied his partner's face as the woman squinched her face in thought.

"You think someone is manipulating events behind the scenes to get Ritsuka sent to a certain place at a certain time?" the genius asked as she looked at the ground for a second as she thought. "But then who would do this and why," she asked again, she couldn't say she didn't see this possibility it had been a rushed off to Japan there could very well be some truly troubling people behind the scenes.

"I have an idea of who but it's the way that I'm not quite sure about it just yet." the Detective spoke taking yet another puff of his pipe and followed her with his eyes as she moved, she looked like she was unconcerned but he could gears turning in the woman's head.

England, Clock Tower 7:30 pm. Wizard Marshall's office.

The old man was not usually at the Clock Tower at this time or ever really especially in this world-line one where the gods hadn't had their arses handed to them on the proverbial silver platter, by Sefar and magic hadn't diminished as much as a result, but the old trickster knew he'd have a visit from a most esteemed guest this evening had set things up for the redheaded lad to show, and sure enough, the person he was waiting for appeared from a magic circle on the floor, and emerging from the portal was a red-head with long-hair and sleek Black armor and behind him, a woman with long gray hair put into twin braids going down her back and wearing a maid uniform.

"Kischur Zelretch Schweinorg. We need to talk." the redhead said placing his hands on the desk between them. Zelretch cracked a sly smile and folded his hands under his chin as he leaned forward on the table.

"And what do owe the pleasure for this meeting, Sirzechs Lucifer." the older man spoke. "And should I brew some tea?"

Kuoh Academy, old school building.

After hearing her queen's findings, Rias promptly informed both Sona and her brother. Sona, in turn, relayed the information to her sister without delay.

"A mage appearing from nowhere that would explain his absence from school for the past two years but why would the boy show up now?" Rias spoke covering her face with her hands as she thought. (It was hard to believe the boy would get past the screening without being shown to have magic at his disposal) she thought and leaned back in the chair her peers standing in front of her desk or even on a couch off to the side munching on some treat.

"I think we should get some information from him via hypnotizing him and he tells us," Akeno suggested. It was a solid suggestion they could get the info they needed and he'd be none the wiser.

"No, I already informed my brother of this, let's wait for brother to contact us back but Konkeko and Kiba I'd like you to keep an eye on the boy. I'll advise Sona to do the same with some of her peerage."

A/N: Hey there! Just-your-average-berserker here, jotting down some final thoughts. Hello-Dark and I decided to write this because we thought it would be fun. While I'm the main writer, Hello-Dark is providing valuable input as I'm still going through DxD and he's much more knowledgeable about it, while I'll be focusing on the FGO side, and this takes place between the bleaching of the plant and just after 1.5 but I'm gonna use servants that I have in my FGO account including a lostbelt servant or two that I have, in my roster. Some of you might be wondering why I chose FGO over Fate/Stay Night and Fate Extra. Simply put, I don't know much about Hakuno Kishinami aside from what was given in Last Encore and Extella Link. As for Stay Night, I think Shirou crossovers with other series are a bit overdone. You also probably realized I kinda left Ritsuka hanging there at the end and I do realize this and I'm gonna pick up with him in the next chapter also I do know that they probably shouldn't be able to feel that Ritsuka killed Goetia and the fact he shouldn't gave any magic ir his command spell at the moment but I think it adds tension and a way for him to stand a chance for what i have coming up, chop it up to autistic license you know? against also im learning about the wizard marshal as i write this so im mot going to write to much of him right now but he is important to the plot bonus points to the readers who guess it, Finally, we have put a M rating on it so we have some wiggle room with what we write.