Author's Note

I just wanted to let people know that yes this is a very canon start of Fate Grand Order, but the divergence and Overlord elements will slowly be added into the story. I hope you guys enjoy it.

Leon-ado

Chapter One "Hero of Justice"

"So, this is the end…" Shirou Emiya muttered as he saw Unlimited Blade Works fall apart around him. "At least, I managed to prevent the collapse of the Age of Man and the return of the Age of Gods…"

Shirou smiled as he felt his life fading away. The existence of Shirou Emiya had not been futile. He had managed to prove EMIYA wrong. It was no wrong to save people. He had struggled against all the odds and come to fulfill the mantle that his adoptive father had passed down to him. Now, he was going to die as a Hero of Justice.

"I wonder if I will meet you again, Saber?" Shirou asked himself as his eyes closed while he drew his last breath and heart stopped beating.

- O -

"Senpai, wake up!"

"Ah..." Shirou groaned slowly opened his eyes.

"Senpai, what are you doing here? Senpai, get up!"

Slowly looking at the girl who was trying to shout to him, Shirou blinked several times, then again and again. He was about to speak up when his brain exploded in pain. Shirou was suddenly overwhelmed by memories. Memories that were… his?

He saw girl wearing a slightly sloppy, without frills, wearing a slightly baggy T-shirt and a blouse. Her purple eyes were covered with square glasses.

"Senpai, are you ok?" The girl worryingly examined Shirou.

"Mashu Kyrielight," Shirou grumbled as he recalled the girl's name from (his?) memories.

"Well, senpai," Mashu smiled. "But still... Why did you sleep in the middle of the corridor?"

Shirou struggled to recall the details. There was simply too much memories that Shirou needed to sort through. He had years of memories and it would take him some time to process everything.

"Senpai? Senpai, you shouldn't drive yourself so hard."

Before Shirou could respond, a rapid movement in the distance of the corridor attracted Shirou's attention. A small creature, looking like a small hybrid between a mouse and a fox, appeared as if from nowhere and made a big leap to Mashu, landing on the girl's shoulder, making her smile and a little bit embarrassed. But nonetheless the girl reached out to rub the neck of the creature.

"Sorry, senpai." The girl pointed to the creature with her chin, slightly embarrassed, "This is Fou, a local resident. Actually, it's pretty rare for someone to see him. So, I think Fou thinks of you as a good person."

Shirou cursed in alarm. All his drowsy and confusion was banished. He jumped away from Mashu and Fou. His mind ran through weapons and tactics that he could use. None of it would work. Only by bringing his greatest trump card to bear that he had even the faintest chance of winning.

Fou seemed to have sensed danger. It pulled its little head forward and sniffed Shirou several times. The creature that had so comfortably rested on the girl's shoulders suddenly jumped away and instantly in one continuous movement rushed to a corner, with such speed that Mashu had to recoil from the force. In one motion, the creature disappeared around the corner, leaving the girl to look surprised at the escaped Fou.

"Oh... He often does this," said Mashu with a smile. "He doesn't show himself much to anyone, so you've already done more than most other people!"

Shirou couldn't help stare at Mashu in a skeptical manner. He could only think up of two reasons why Mashu seemed so carefree. Either she didn't know Fou's true identity or it was no danger to her. Both cases were frightening because Shirou knew only one person that was were not scared by Fou. That individual was Altrouge Brunestud, the 9th Dead Apostle Ancestor.

The fact that Fou, or rather fucking Primate Murder, hasn't gone a killing spree is a miracle. If it wants to pretend to be a cute animal then I will let it, but the moment that Fou becomes Primate Murder is when I put it down even if it costs my life! Shirou vowed to himself. "The cute animal must be looking for something.

"What are you doing here?" A voice from the other end of the corridor made Shirou and Mashu turn to look at the approaching one. The speaker revealed to be a man and a pretty tall one, middle-aged. "Ah, Mashu." The man approaching Shirou only now noticed the girl and waved a hand, after which he turned his attention to Shirou. "And..."

"Shirou…" Shirou replied and he stopped half-way as some of (his?) memories came to him. "…Muramasa."

"Ah, Shirou Muramasa!" The man shouted in excitement as broke into a smile. "My name is Lev Lainur. I am honored to finally meet you! Chaldea wouldn't have become what it has become without the strong support of your clan!"

"I am honored to make your acquaintance," said Shirou as he shook Lev's offered hand. "I am very impressed in your work…" Shirou struggled to recall some details before it came to him. "SHEBA; the Near-Future Observation Lens is masterpiece of magecraft and technology."

"Please excuse me," said Lev as he started to walk away. "I would be like to talk to you longer but there is somewhere I must be right now. Mashu if you don't hurry up you will be late for a briefing from the chief."

"I'm will be right there!" Mashu shouted and she turned to Shirou. "Senpai, I am sorry but the tour I promised will have to happen another time." She started to run after Lev and looked waved back at Shirou. "The meeting shouldn't take longer than an hour. If you still interested I can show you around an hour later."

"I want to join." Shirou smiled as he ran after Lev and Mashu.

- O -

The briefing was long and very informative. It really helped Shirou as it gave him time to examine (his?) memories. Many words and concepts in the briefing also helped as cues to trigger memories that were not his, yet his.

Shirou Emiya, or Shirou Muramasa according to (his?) memories, finally was able to make some sense of what was happening. The world he now found himself was very similar to the one that he had left. Of course, there were several strange differences in magecraft and technology that he had heard from the meeting. There was Chaldea, or formally known as the Chaldea Security Organization, which was setup to prevent the certain extinction of mankind. Chaldea also had the ability to transport people through time.

He still had a lot of memories to still sift through, but Shirou was confident that he was able to blend in well without causing any problems. The rest of his memories of Shirou Muramasa could wait as there were several alarming questions that Shirou had. The first was that he should be dead and there should've been only two results; reincarnation with his memories wiped or entering the Throne of Heroes as a Heroic Spirit, whose legend had earned him the title of Hero of Justice. The second was how did he ended up fusing with one of his countless parallel selves in the multiverse.

"Well, hello there!" A voice called out.

Shirou snapped out of his musing when he saw a man sitting on a bed. A blue-eyed blond man with long hair tied in a ponytail would have been considered at least handsome, while here he was no more than an ordinary guy dressed in a white medical coat. The man appeared did appear particularly normal. At least that was to most people. Shirou had interacted with just about every sort of human. He could perceive many things that escaped the notice of most humans.

This man is no ordinary human… At one point, he must have been an incredible capable and accomplished mage. He could have given Zelretch and Merlin a run for their money in his heyday. I wonder what must have happened to cause some much damage to his Magic Circuits that he is basically a normal human now? Shirou thought as he looked at the man. "Who might you be?"

"Romani Akkiman!" The man introduced himself. "A modest doctor at your service."

Shirou resisted the urge to cough. If Shirou hadn't been able to notice Romani's Magic Circuit and his likely past glory then Shirou might have believed Romani's words.

The room in which Shirou found himself in did not look like a medical office. It couldn't be. Shirou might have been lost in his thoughts, but he had been half-aware of his surroundings. This room was clearly his. A normal bedroom with a small bed with a wardrobe, a desk and a small monitor hanging quietly on the wall.

"And what is a doctor doing in my room?" Shirou asked he took a step then pulled out a chair from the desk and sat so that he could look into the eyes of the doctor.

"Who are you? You are not Shirou Muramasa." Romani said in firm tone.

Shirou wondered how he should respond for a couple of seconds before coming to a decision.

"Shirou Emiya," Shirou bluntly replied.

"Any relations with the Mage Killer, Kiritsugu Emiya?" Romani asked with narrowed eyes.

"Yes, but not the Kiritsugu of this world or timeline." Shirou responded.

"World? Timeline?" Romani repeated with wide eyes. "The fact that I don't notice any abnormalities of your body and soul narrows down my suspects. I also detected the presence of Counter Force. Not that of Gaia, but Alaya. What's your relationship with Alaya? Are you a Counter Guardian?"

Shirou become overwhelmed by Romani's words. When he heard Romani's conclusion Shirou nearly fell of his chair.

"Counter Force, Alaya, and Counter Guardians." Shirou repeated in disbelief. "You seem incredible familiar with those topics. Something that shouldn't be possible as most knowledge regarding the inner working of those subjects is highly regulated by the Mage's Association. Who are you?"

"Just a regular medical doctor," Romani smiled. "If I was you I would be more concerned about myself. A single word from me and you will be overwhelmed by Chaldea's security forces; which are made up of special forces operatives, Enforcers and Executors."

Shirou remained calm. He didn't take Romani's threat too seriously. Special forces operatives, Enforcers and Executors were something he could handle. Suddenly he shivered as he recalled Fou. If Romani miraculous had any control over Fou then Shirou was screwed.

"I have my secrets," said Shirou as a scroll materialized in his hands. He threw the paper scroll at Romani. "This should calm your paranoia."

The medical doctor caught and unraveled the paper scroll. He quickly looked over the paper scroll and rerolled it. The paper scroll disappeared and Romani seemed like he was no longer too suspicious at Shirou.

"This geas will be enough for now," said Romani with a smile. "You can keep your secrets, but I hope you open yourself up to me."

Romani walked over to the door when it opened to reveal a man in extravagant attire.

"Romani? So here you are!" Lev exclaimed as he found the man he was looking for. "What are you doing here? Reyshifting is about to begin soon, shouldn't you be present? Team A seems to be doing well, but Team B is all on the nerves. Can you give them some sedatives?"

"Mmmmm, maybe." Romani sighed and rose from his seat then he stretched.

"Hurry up, Romani." Lev said in an exasperated tone as he left the room.

Romani quickly chased after Lev. Shirou followed as he was interested more about Romani and wanted to see what Romani was capable of. It was too long when Shirou found himself in a large medical room.

He really seems like a normal medical doctor, Shirou noted as he observed Romani at work. No one would really know that he must've been an incredible mage in the past.

Shirou was about to continue with his observation of Romani at work when his instincts warned him of danger. He didn't know what sort of danger he faced, but Shirou allowed his instincts to guide his actions.

"Rho Aias!" Shirou shouted as he summoned the Noble Phantasm of Aias the Great.

A semi-transparent, six-petalled pink flower formed around Shirou. Soon several layers manifested. Seven layers that possessed the defensive power of a fortress wall covered the people inside the room. The explosion caused damages to the outmost, first layer of Rho Aias, but the other layers remained undamaged.

"Jesus Christ!"

"Shit, what just happened?!"

"Was this an accident?"

"Someone is trying to kill us!"

The room was soon flooded with the voices of terrified people. There were some that rather clear-minded, but those were a few. Shirou quickly tuned out the voices and surveyed the room for anymore dangers. He didn't notice any more danger besides the hidden explosives that had already exploded.

Almost immediately the dark room was lit up with the red light of the emergency lamps, and at the same instant a voice rang out over the loudspeakers placed in all the rooms.

"Emergency. Emergency. Fire in the central power station. Fire in the central control room. All personnel must be evacuated from the second gate. Gate closure will occur within ninety seconds. I repeat, an emergency..."

"Jesus Christ!" Romani swore. "Bring the central office to the monitor!"

The monitor that hung so calmly on the wall of the room instantly blinked at the command after which it quickly charged up with a manifesting picture. The picture that appeared on the screen did not inspire optimism at all. Upturned tables, scorched walls, cracks on the walls all the way to the ceiling, crushed equipment. It seemed as if a bomb had exploded in the room.

"Mother of God!" Romani cursed again then turned his eyes to crowd around him. "Is anybody injured?"

The response was almost instantaneous. Romani and the other medical professionals in the room rushed to conduct medical examinations. Many people seemed injured at first, but Romani and other medical found no one was injured except for a few cuts and bruises. The most serious cases were shock and mental trauma.

"Find shelter and hide! The gates are about to close, you need to leave!" Romani shouted as he started to direct the evacuation.

Shirou remained silent as he continued to observe. There were professionals doing their jobs attending to the duties. He just looked out for any dangers that he needed to deal with. To his relief, there seemed no more dangers and he just remained as a vigilant watcher. Soon only Romani and Shirou was the only ones left in the room.

"You come with me!" Romani shouted as he pointed at Shirou. "We need to get to the control room!"

Romani almost flew off and rushed into the control room, Shirou followed him. Soon they found themselves at the front doors of the entrance to the control room, which now looked pathetic. Twisted pieces of metal were stuck in the wall preventing the doors from opening completely so that they can squeeze through them.

"By the Lord!" Romani cursed.

Shirou summoned Kanshou and Bakuya. The Noble Phantasms cut through the metal with ease. Romani immediately rushed inside as the obstructions were cut away by Shirou.

"Mother of..., the bomb exploded here!" Romani glanced at his surroundings. "But how did…"

"Reduced energy levels. Energy generation is insignificant..." The warning system immediately responded. "Automatic power supply change is impossible. Staff please manually change the power source. The doors will close in forty seconds. Please, all staff personnel..."

"Power supply!" Romani grabbed his head. "It's in the basement for replacement! I will handle the power issue. Try and look around if you find any survivors!"

With these words, Romani left the room, but before Shirou himself could think about the doctor's suggestion another warning distracted him.

"Transition to the final stage of reyshifting. Coordinates: 2004; January 30; Fuyuki; Japan. Materialization of the Laplace system. Adjust the time factor of the singularity. The summoning program is carrying out. Please prepare the masters..."

A quiet sound from the destroyed console caught Shirou's attention. Instantly, Shirou jumped towards it and, raising the wreckage above his head, was able to detect the source of the noise.

Mashu looked pitiable. It seems that the console crashed into her with the force of the shock wave, and then pressed her into the wall, literally breaking the girl in half. Blood flooded through the tears in her clothes, that hid the mutilated body of the girl, bent by an explosion.

"S... Senpai" Opening her eyes, Mashu focused them on Shirou instantly. "Everything is all right... Run... Leave me... You need to leave…"

However, before Shirou could respond to such words, another alert broke into his mind.

"Warning to all supervising personnel. The status of Chaldea is changing. S.H.E.B.A. observes a change in the foreseeable future. The absence of signs of intelligent life on earth over the next hundred years. The survival of humanity is not guaranteed."

Mashu's eyes widened to these words while Shirou's gaze was fixed on a rapidly changing color for the Chaldea's oncle blue - and now red core.

Literally a second later, the loud crash of a metal partition that struck the floor distracted them both.

"The interior is closed. Starting to clean the interior... "

"Too... Too late..." Mashu said plaintively, at the moment when she realized her doom. "The doors... Are closed..."

Shirou resisted the urge to playful retort at Manshu's words. A few metal blast doors were nothing to him.

"There is no possibility of reading the vital signs of the Masters' capsules" The cold metallic voice of notifications was heard again. "There are not enough masters to complete the reyshifting procedure. Search for potential masters... A potential master was found. Installation of master number forty-eight as a priority master" At this moment Shirou felt how the gaze of a mechanical, insensible mass shifted to him. "The process of conversion of the Heroic Spirit begins..."

"Mashu, hold on!" Shirou shouted.

"Senpai, it…" Mashu fell silent as she saw Shirou grabbed the rumble bearing her and threw it aside as if they weighed nothing. "Never mind…"

Shirou quickly inspected Mashu's wounds. They were nothing too serious. Miraculous Mashu had not suffered any fatal wounds. She was sturdier than she appeared. The worst that Shirou had deal with to prevent Mashu's injuries from becoming worse was to stem the bleeding. Something that Shirou could easily handle.

He was about to seal Mashu's bleeding when light appeared around him and Mashu.

"The reyshifting procedure was launched. The Grand Order Demonstration is running. Transfer - Fuyuki..."

What do you guys think? Hope you guys enjoyed it. Please leave your comments and criticism on the reviews. The more detailed the better, will allow me to see my flaws and fix them.

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Leona-do