Pseudo-servants are Servants that have manifested utilizing humans as their vessels. While like Demi-Servants in the result, the process of forming one is different. Pseudo-Servants are the result of Heroic Spirits and Divine Spirits that cannot become Servants due to an inability to take a physical form, so they are instead summoned by using a compatible human body to act as a vessel. The resulting Servant cannot be called either individual, but a combination of the powers of both individuals mingling together that add abilities do not present in the original Servant. The thoughts and personality may fully conform to that of the human vessel as well should the spirit decide that it is best to give over control or if the human vessel's will overpower the spirit's, or it may manifest as a combination of their respective personalities. However, if the possessing spirit is a Divine Spirit, the human vessel's memories and past will be sealed to protect the vessel's mind regardless of how the personality manifests.
In Shirou's case, despite being the pseudo-servant vessel to Sengo Muramasa, he still retains his mind and actions and gained his noble phantasm. However, they can switch minds if they want to.
Normally, it would not be possible to split the heroic spirit from the vessel itself...
Until now that is...
Right now, it is lunch time in Chaldea's cafeteria. Normally, it meant that Shirou would be at the cafeteria catering to Arturia and her counterparts, Ishtar and her counterparts, Parvati, Kama, BB and her sisters, Illya and her counterparts, Miyu, Astraea, Irisviel, Jaguar-man, and Kiritsugu alongside with EMIYA and EMIYA Alter helping him.
However, today was different from their usual days.
Because Shirou was not here yet.
However, unlike before, everyone was not worried as they knew that Shirou was stuck doing something for Da Vinci.
"Hey, Shirou's not here yet," Arturia Alter said.
"Relax. He's just stuck doing something for Da Vinci again," Arturia said.
"Yeah. And when it comes to her, she's bound to ask him to do something crazy again, even if it's not an experiment," Arturia Lily said.
"Indeed. Remember the last time Shirou was late here?" Lancer Arturia asked.
"Oh yeah. That was the time he got turned into a girl, correct?" Lancer Arturia Alter said.
"Yes. To be fair, that time was Merlin's fault," Ruler Arturia said.
"Exactly. Then there was that time where Shirou got turned into a kid because of a youth potion made by Da Vinci herself," Archer Arturia said.
"Eh? That happened before?! Along with Shirou turning into a girl by Merlin?!" Caster Arturia said in shock.
"Yeah. And we had to watch over Shirou when he was turned into a kid for a while," Rider Arturia Alter said.
Santa Arturia Alter nodded in agreement. "And he was so cute, I'll admit..."
"Wow...just what did Shirou look like when he was a kid?" Caster Arturia asked.
Mysterious Heroine X let out a smile. "He was so adorable!" she said happily.
"Yeah. He was so adorable that when it was my turn to watch over him, I have him a few of my sweets I've been saving up," Mysterious Heroine X Alter said.
"And don't get me started on when he wore those bunny ears..." Mysterious Heroine XX said as she fondly remembered the time Shirou wore Ruler Arturia's fake bunny ears as a kid.
"Wow..." Caster Arturia said in amazement.
"Mou! Where is Emiya-Kun?!" Ishtar asked in annoyance.
Ereshkigal let out a sheepish laugh. "Relax, he's just busy with either a personal issue or Da Vinci's got him again," she said.
"Still though, he's taking too long in my opinion..." Rider Ishtar said.
It was then that Astraea let out her usual laugh. "Ishtar, you seriously have no patience! Well, that's expected from a lowly goddess like you! Ohohohohohoho!"
Enraged by Astraea's laugh and insult, both Ishtar and Rider Ishtar immediately went for Astraea and started a fight against her while Ereshkigal let out a sigh. "Not again..."
"Senpai's late again..." Passionlip said.
"Hmph. I bet he's just busy with one of Da Vinci's schemes again," Meltlilith said.
"You think so?" Kingprotea asked.
"Obviously."
"Fufufufufu...senpai better not keep me waiting...or else BB chan will come and haunt hum..." BB said creepily.
"Hey!" Passionlip, Meltlilith, and Kingprotea yelled in unison.
Parvati let out a sigh. "If BB is based off from me from another world...I don't want to know what that world's counterpart of me is like..."
"Neither do I. It's actually scary to think about it, even for me," Kama said.
"Hm...Da Vinci, hurry up with what you're doing with onii-chan..." Illya muttered.
"It feels like Da Vinci is hogging onii-chan a bit too much lately..." Kuro said.
"I agree. It feels like Da Vinci has some excuse to grab onii-chan every day..." Miyu said.
"I know right?" Sitonai said.
"Mou! Shirou! Get your butt here! Onee-san is hungry right now!" Jaguar-man yelled.
Irisviel let out a sigh. "Jaguar-man calm down," she said as she rubbed the top of her head, trying to calm her down.
"But Shirou's taking his business too long! I need food!" Jaguar-man replied.
Irisviel sighed again. "Just wait."
Kiritsugu did not say anything. Meanwhile, EMIYA and EMIYA Alter were having thoughts of their own.
"Jeez, what's Da Vinci up to with my younger self...hopefully it's something that doesn't involve any crazy experiment that either turns him into a girl or changes his age..."
"Da Vinci, whatever you're doing with my younger self, you better hurry up..."
It was then at that moment, Shirou came into the cafeteria. However, what happened next completely surprised everyone in the cafeteria.
A person was next to him, and that person was Sengo Muramasa, Shirou's ancestor who was supposed to be residing in Shirou's reality marble.
For a moment, everyone stopped what they were doing and looked at the scene in shock.
"Um...Shirou...is that-" Arturia asked but was cut off from Shirou answering her question.
"Yes Arturia. Sengo Muramasa is right next with me now," Shirou replied with a sigh.
"Hey. It's been a while since I've seen all of you. How all of you have been?" Sengo asked.
For a moment, nobody did not do or say anything. Then everyone besides Kiritsugu, EMIYA, and EMIYA Alter let out one reaction.
"EHHHHHHHHHHHHHHHH?!"
At that moment, Shirou, Sengo, Kiritsugu, EMIYA, and EMIYA Alter covered their ears upon hearing the loud collective voices from the girls. "Damn, they're loud..." Sengo muttered as he sat down on a chair along with Shirou.
"W-W-W-What is this?!" Jaguar-man yelled. "How can both of you be here?!"
"Exactly. It should not be possible to separate a heroic spirit from the pseudo-servant vessel itself! And furthermore, Emiya-kun is already a heroic spirit!" Ishtar yelled.
"How is this possible?" Parvati asked.
Sengo let out a sigh. "Well, blame Da Vinci for this."
Everyone felt like groaning upon hearing Da Vinci being involved in this situation. "I knew it. It's always Da Vinci..." they muttered in unison.
Meanwhile, EMIYA and EMIYA Alter let out a sigh. "Okay, what happened this time?" EMIYA asked.
Shirou let out a sigh. "It's a long story. What happened was that earlier, Da Vinci asked me to be a part of one of her experiments as usual."
"And what experiment did Da Vinci create this time?" Irisviel asked.
"Well, it was a device that had the ability to separate the inside of an object from the object itself. However, the device worked a bit too well, and-"
"It resulted in you and Sengo Muramasa splitting from each other. Am I correct?" Kiritsugu asked.
"Yeah."
Arturia and her counterparts, Ishtar and her counterparts, Parvati, Kama, BB and her sisters, Illya and her counterparts, Miyu, Astraea, Irisviel, and Jaguar-man looked at both Shirou and Sengo in wonder over how both are in the cafeteria. Upon receiving the attention from the girls, Sengo got a little annoyed.
"Hey! Give me some space here! You're creeping me out with those stares of yours!" he yelled, causing everyone to stop staring at both Shirou and Sengo.
Shirou let out another sigh. "Sorry, but this is probably the first time seeing both me and you outside of my reality marble."
"So...how do you feel now onii-chan?" Illya asked.
"Hm? What do you mean by that?" Shirou replied.
"Well, since that Sengo Muramasa is separated from you, do you feel different now? Like for example, do feel weaker right now?" Kuro asked.
"Well honestly Kuro, I don't feel anything different actually."
"I see." Kuro then turned to Sengo Muramasa and got out of her seat. "Hey, Sengo Muramasa."
"Hm? What is it, you little kid?"
Kuro was a little annoyed but continued the conversation. "Well, how does it feel to be here? Well, in your own body that is?"
"Hm? Well, it's not that different compared to the time where I possessed my host's body for a day, so no big deal."
"I see...well, glad to know," Kuro said as she got back to her seat.
"Shirou, how long is this going to last?" Arturia and her counterparts asked.
"Hm...I would say about a day at least, I think. Or two," Shirou replied.
"So yeah, until the day or two passes, me and my host will be separated for a while," Sengo said.
"I see...well then, that leaves one question," Ishtar said.
"What is it?" Sengo asked.
"Well...how are we going to tell different between Emiya-kun and Sengo Muramasa?" Ereshkigal asked.
"That's true. You two look so similar that it's hard to tell the difference between the two. Not to mention the fact that both of you wear the same clothing..." Astraea said.
"Yeah. Even now, I'm already getting confused..." Jaguar-man said.
For a moment, everyone in the cafeteria was wondering for a solution on how to tell the difference between Shirou and Sengo.
However, it was then Sengo had a solution.
"Hey, can you project a smoking pipe for a moment?" Sengo asked Shirou.
"A smoking pipe? Well...yeah, give me a moment," Shirou replied as he began to project a smoking pipe. Within a few seconds, a smoking pipe appeared in Shirou's hand. "Here," he said as he handed Sengo the smoking pipe.
"Thanks. Hey, does anyone have a lighter?"
In a surprise turn of events, Kiritsugu threw a lighter at Sengo, which he caught it. "Here," Kiritsugu said.
"Thanks," Sengo said as he lit up the smoking pipe and let out a few puffs of air. "Anyways, this is how one should be able to tell the difference between me and my host. If one of us is holding a smoking pipe, the one that's holding the smoking pipe is me."
Everyone was quiet for a moment and stared at Sengo again, making Sengo confused for a moment. "What?"
"Hm? Oh, it's nothing..." they all said in unison. "This feels weird. It's like seeing Shirou/Emiya-kun/senpai/onii-chan/Sherou smoking...and for some reason, it doesn't fit him."
"By the way Sengo Muramasa, can I ask you something?" Jaguar-man asked.
"Huh? What is it?"
"How old are you?"
For a moment, everyone was silent upon hearing Jaguar-man's question. Then the silence was broken upon hearing Sengo's answer.
"I'm 72 years old. Why?"
"EHHHHHHHHHHHHHHHHHHHHHHHHHHH?!" Everyone exclaimed in surprise, making Sengo cover his ears again.
A day has passed since Sengo Muramasa was separated from Shirou's body and was given a temporarily body, and the result was confusing. Some of the staff and servants were confused between the two. However, when Sengo brought out the smoking pipe, the servants and staff were able to recognize which one was the other.
And the reactions varied based on the servants themselves.
In Cu and his counterparts' case, they were confused with which on was which...until Sengo brought out the smoking pipe.
In Medusa's case, she was confused as well.
In Medea's case, she looked at Sengo in envy, for reasons that both Shirou and Sengo have no clue why.
In Sasaki's case, he was amazed and asked Sengo to create a Muramasa blade for him.
In Hercules' case, he did not care.
However, in Gilgamesh's case, he freaked out and went on a rampage. Luckily, his counterparts managed to stop him before he could...although they were too late as Sengo already knocked him out with one of his punches.
In Nero's and her counterparts' case, they were amazed and wanted Sengo to be their model one day.
In Jeanne D'Arc and her counterparts' case, they were surprised for a moment until Sengo made a joke about how Jeanne D'Arc Alter looked like a ghost, which then turned into an argument between Jeanne D'Arc Alter and Sengo Muramasa.
In Okita's and her counterpart's case, they were amazed with how they were separated from each other. However, Okita Alter wanted a Muramasa blade, much to Okita's disbelief.
In Musashi's case, she was overjoyed to see Sengo again, and asked him many questions.
In the Knights of the Round case, they were surprised and asked Shirou if Merlin was up to the separation of Shirou and Sengo, which Shirou replied with a no.
In Merlin's case, he was surprised and was a little jealous of Da Vinci when Shirou told him that Da Vinci was the reason Shirou and Sengo separated.
In Waver's case, he got a serious headache upon seeing the two.
In Amakusa Shirou's case, he was confused between the two.
In Jack's, Paul's, Nursery's, and Abigail's cases, they were shocked to see them.
In Hakuno's case, she was shocked to see Shirou and Sengo separated, and was even more surprised to see that Sengo looked at lot like Shirou.
In Sieg's case, he had the same reaction as Hakuno's.
In Scathach and her counterparts' case, they were amazed with the situation.
In Proto-Merlin's case, she was surprised with how Shirou and Sengo separated, and started to even flirt with Sengo, much to Shirou's dismay. Luckily, Sengo immediately knew what was going on and bonked her on the head.
In Ritsuka and Mashu's case, they were surprised with how Da Vinci managed to separate Shirou and Sengo.
And in Da Vinci's case, she was pleased that her invention turned out to be a success.
Right now, Shirou was in the hallway, looking where Sengo was. "Jeez, I leave him alone for a moment and he's gone. Just where he could be?" As Shirou continued to walk around in the hallway, he came across a group of people who were gathering around in one of the recreational rooms. "Hm? What's going on over there?" he thought. Shirou then got closer to the group and immediately knew what was going on.
It was Sengo Muramasa having an arm-wrestling match with one of the male servants.
"Ora!" Sengo yelled as he slammed his opponent's arm down to the ground.
"Ow!" his opponent yelled as he rubbed his hand.
"And the winner is Sengo Muramasa, who is on a streak right now!"
Sengo let out a smirk. "Better luck next time kid." His opponent then left the chair he was sitting on. "All right! Who's next!"
Shirou was in disbelief for a little. "Wow. So that's where he was...in an arm-wrestling match..."
Sengo then noticed Shirou and let out a smirk. "Hey, my host! Get your butt over here!"
Everyone then turned around to see Shirou. Shirou let out a sigh. "Really Sengo?"
"Hey! It's been a while since I've been here, so I need to let out some steam occasionally! Now get your butt over here or else I'll drag it here for you!"
Shirou sighed again. "Guess I got no choice then..." he thought as he then sat on the other chair, raising his arm. As he did, Sengo then grabbed his arm with his other arm.
"Okay! Ready...go!" one of the servants said.
Soon, Shirou and Sengo were in an arm wrestling match, both arms were not budging on each side. "Damn...my host seems to be stronger than what I expected..."
"Wow...this is Sengo Muramasa's arm strength...then again, he is a blacksmith..."
For a moment, both sides were struggling to get one side to fall, neither were giving up.
"Damn it...I will...NEVER...GIVE UP!" they both thought in unison.
However, it was then that the table there were on couldn't handle the pressure...and broke into the two, forcing both of them to fall to the ground and creating some dust in the process.
When the dust settled, it revealed the outcome.
It was Sengo Muramasa's win.
"Well then...looks like I win," he said with a smug grin on his face.
Shirou let out a small sigh while everyone else cheered.
"Jeez. I know that we look a lot like each other, but this is getting ridiculous..." Sengo said as he let out some air in the smoking pipe.
"Well, to be fair, nobody has seen both of us like this here, so you can't blame anyone having a reaction from seeing us like this," Shirou said.
"True. I just wish that people wouldn't be this shocked over something like this..." he muttered.
As Shirou and Sengo continued walking down the hallway, it was then they bumped into a certain person who was completely shocked ever since she arrived in Chaldea.
Olga Marie Animusphere.
"Hey Shirou! I need to you to do...some...thing..." Marie said as she slowly stopped speaking upon seeing both Shirou and Sengo.
For a moment, Marie was completely stunned and shaking while pointing at both Shirou and Sengo, causing Sengo to look at the woman in confusion. "Hey, little lady, is there something wrong with your brain?" he asked.
Upon hearing Sengo's words, Marie immediately snapped out of it. "Huh?! There's nothing wrong with my brain! It's as fine as it is! A-Anyways, what is this?! How are there two of you Shirou?!"
Shirou let out a small sigh. "Director, the person next to me is Sengo Muramasa, the heroic spirit that became a part of me who happens to be my ancestor."
Marie's mouth dropped even further. "Huh?! That's Sengo Muramasa, the heroic spirit you fused with to become a pseudo-servant?! And he's your descendant?!" she yelled in shock.
"Y-Yeah," Shirou said.
Sengo let out a sigh. "Jeez little lady, you scream really loud..." he muttered.
"How is this possible?! It shouldn't be possible to separate a heroic spirit from the pseudo-servant vessel itself! And even if it was possible, you're already a heroic spirit! How?! How?!" Marie yelled.
"Well, ask Da Vinci for that question. And honestly, I don't know either," Shirou said.
Marie let out a groan while facepalming herself. "Damn it...I should have known...that servant always had a knack of making conducting experiments with any of her creations..."
"Director? Are you all right?" Shirou asked.
"Y-Yeah. Just...trying to figure this shit out..." she muttered softly. "Anyways, is this damage going to be permanent?"
"Well no. Da Vinci said this will probably last a day or so."
Marie let out a sigh. "I see. Anyways, go on with your business you two. Also, Sengo Muramasa?"
"What?"
"I'm not little!" she yelled before she started to walk away.
"What's with her problem?" Sengo asked as he was confused.
"I don't know," Shirou replied.
Shirou and Sengo then continued to walk down the hallway. As they did, they came across a certain servant who arrived as well.
Romani Archman.
"Hm? Hey there...Shirou..." Romani said as he slowly stopped speaking upon seeing both Shirou and Sengo together.
Shirou let out a sigh. "Here we go again..."
"Um...Shirou, who's that person over there? And why does he look like you?" Romani asked.
"Romani, the person next to me is Sengo Muramasa, the heroic spirit that became a part of me who happens to be my ancestor."
Romani was surprised a bit. "Eh?! That's your ancestor, Sengo Muramasa?! But he looks a lot like you! I can understand since he was your ancestor, but this is unreal!" he said with amazement.
"I get that a lot."
"Hey, who is this person?" Sengo asked.
"Ah, this is Romani, Chaldea's doctor," Shirou said.
"I see. So, you're the doctor the kid was talking about earlier."
"Kid? You mean Ritsuka?"
"Yeah. During the first time I met him, he would talk about you sometimes."
"I see...anyways, nice to meet you Sengo Muramasa," Romani said as he raised his hand for a handshake.
"Yeah. Nice to meet you too," Sengo said as he shook his hand as well.
Soon, both men were done with their handshake. "Anyways, I got to go now. See you later Shirou! Sengo!" Romani said as he soon began to leave.
"Yeah! See you!" Shirou said.
Soon, Romani left, leaving Shirou and Sengo alone. "He seems to be a nice guy..." Sengo said.
"Well, he is."
"I see." It was then that Sengo's body began to light up. "Well, looks like time's up."
Shirou turned around to see what Sengo was talking about. As he did, he immediately knew what he was talking about. "Yeah. It seems you're going back to my body now."
"It seems so. Anyways, give that genius over there my thanks," Sengo said as his body began to disappear.
"Will do."
Sengo let out a smile. "Well, see you later."
And then, Sengo's body turned into particles of light and went back into Shirou's body.
Omake
Shirou was walking down the hallway towards the cafeteria. As he did, he came across a sight he never thought he would see.
Which was Sengo Muramasa, behind the kitchen counter, making rice balls.
"Eh? That's Sengo Muramasa. And he's making...rice balls? He can actually cook? This is new," Shirou thought as he looked at Sengo making rice balls. Eventually, Shirou headed into the kitchen, when Sengo noticed.
"Hm? Oh, hey there my host."
"Sengo Muramasa, are you making rice balls?"
"Yeah. Why? You want some?"
"Sure." Sengo then handed Shirou one rice ball. As he did, Shirou took a bite out of the rice ball. "These tastes good. I didn't know that Sengo Muramasa was able to make rice balls...or the face that he's able to cook."
"Well?" Sengo asked, snapping Shirou out of his thoughts.
"It's not bad. I'm surprised actually."
"What? The fact that I can cook?" Sengo asked with laughter in his voice. "My host, there are a few things that you don't know about me. And this is one of them."
"I see..."
As Shirou and Sengo were talking, it was then that they received multiple guests in the cafeteria.
Which was Arturia, her counterparts, and Musashi.
And they all have eyes filled with hunger while staring at the rice balls.
"Um...Sengo Muramasa...I think the smell of your rice balls attracted some people..."
"Seems so."