Shirou Emiya was having a normal day just like any other wake up, practice magecraft, make breakfast, eat it with Sakura and Taiga, go to school, fix things around school, listen to his friend Issei tell him how much of a devil Rin is, stay late after school for some reason then go home. Yup a normal day for Shirou however this normal day pretty much went to shit when he was walking home, that's when he ran into a girl she had a child like look with white hair and crimson red eyes She wears a collared purple long sleeved shirt with a light purple scarf to match and a long white skirt with purple boots she looks at Shirou.
"You better summon your servant onee-chan or you'll die." Shirou looked at her in confusion.
"What do you mean summon my servant?" He asked the girl looked at him in annoyance
"Kiritsugu really didn't tell you anything." That caught his attention.
"How do you know my father, who are you?" the girl got mad how was this the kid that Kiritsugu abandoned her for he was nothing special yet he choose this boy over her, his own daughter this really pissed her off.
"BERSERKER!" She yelled at the top of her lunges the out of nowhere appeared giant it stood at 8'' tall it was huge like a massive bodybuilder on hulk steroids it had a big black mane for hair and muscles so hard that it looks like you can grind anything down on them in it's hand is a giant shredded edged sword looking thing that looks like a giant stone the little girl gave a very dark and evil smile.
"Berserker kill him!" The Giant gave a loud roar that echoed the street and the behemoth monster charged at Shirou he was paralyzed by fear, he did the only thing he could do run away run away really fast. He took off like a bullet but the beast was immensely faster it easily caught up to Shirou. It took it's massive sword and swung at Shirou just then he tripped and the blade barely missed him, but that didn't stop Berserker from kicking this sent Shirou's body into instant pain shock as he felt the bones in his body break and crack under the pressure Shirou was sent flying into a building. Shirou hit the ground hard he briefly fought off the pain long enough to realize where he was oh I'm home he thought. As he laid in his now wrecked shed he tried to move around but his body couldn't he looked to see the monster and that little girl.
"To bad for you onee-chan that you had to die now." She said her words held venom and malice in them. Berserker raised its weapon crap I don't want to die now not when I haven't done anything not when I didn't keep the promise I made to my father Kiritsugu. He closed his eye waiting for the final blow but it didn't come he opened his eyes and saw a woman with golden blonde hair and aqua green eyes she had a blue dress covered in steel armor she was wielding a lance which seemed wrap around her hand, which was currently blocking Berserkers massive weapon the woman then tilted the lance and made Berserker lose it's balance she then kicked the monster backwards the girl looked at Shirou and the she cracks a smile
"It seems you're not worthless after all goodbye onee-chan." the little girl said as they walk away.
"On no you don't." The woman said as she starts going after them.
"Wait." Shirou managed say the woman looked at Shirou.
"Are you sure?" she asked.
"Ya she's leaving so don't go after and cause more trouble." The woman looked at him and nodded.
"Alright I believe I have yet to introduce myself I am Lancer and it would seem you are my master." Lancer said.
"Master what's that mean?" He said then Lancer looked around like something was wrong.
"There is another master and servant here I will take them out." She said as she started to move Shirou couldn't believe what he heard she was going kill people without a second thought. Shirou focused his body and slowly started to get up his body screeched in pain.
"Wait Lancer don't kill them." he said Lancer look at him in confusion.
"Don't kill them." He said she stopped for a moment then nodded.
"As you wish master." she said.
"Good." he said as his vision started to fade he started falling forward the blackness...
Shirou saw things he couldn't believe he saw it was about a woman who wielded a beautiful and elegant sword in one hand she prevailed for her people giving everything for them. Shirou opens his eyes his head racking in pain along with his whole body he manages to look around to realize he is lying in his bed then his eyes catch something else he sees Lancer sitting in the corner of the room she notice I woke up
"Oh good you're up." She said so what happened yesterday really happened he thought then he thought about it he really doesn't remember what happen after he met Lancer.
"Um what happened yesterday?" She looked at him like she was trying to figure out what to say.
"You passed out after telling me not to attack the master and servant that were approaching." That made him remember about the other master.
"What happened to them?"
"In a way it was a good thing that you told me not to kill them because the master is the one who healed you." Lancer said.
"I see." he said as he got up
"Well I guess I'll go make something to eat."
"About that master." Lancer said as he walked into the other room to see.
"Hello Shirou." He looked at who said it when he realized it was Rin then, he noticed a silver haired man in red clothes cooking in his kitchen the two questions that popped in his head were why is Rin here, and who is in my kitchen. He put more emphasis on the kitchen question then the man stepped out.
"Ah good Shirou you're awake what would you like since I'm making breakfast." He said in a nice manner Shirou took a deep breath.
"Rin what are you doing here? and who is this man in my kitchen?" he said calmly Rin shot a sly smirk.
"Is that any way to treat a guest Shirou especially another master." This made Shirou freeze.
"What you're a master? Are you the one who healed me?" Rin gave him a questionable look.
"No it was a flying dog of. who do you think healed you!" She yelled like it was obvious.
"Still you healed faster than I thought you would."
"Oh I see thank you Rin. Now onto the real issue." Shirou paused for a moment taking a breath.
"WHO IS IN MY KITCHEN!" He yelled this completely made Rin fell over this idiot cares more about who's in his kitchen than the fact that he almost died she thought.
"Well you were passed out and I was hungry so I was going to cook but Saber wanted to instead so I let him." Then Saber came out of the kitchen with a happy look on his face.
"It's done." After everyone sat at the table eating Saber sighed in relief It's been a really long time since I got to cook let alone in my kitchen he thought to himself. Now I just need to get ball rolling if this Shirou is similar to me then he should be using his magecraft wrong. He remembered how he use to make makeshift magic circuits and how badly that damaged his real magic circuits and his body. all I need to do is steer the conversation in that direction. He looked at everyone at the table truly enjoying his food which brought joy to him it felt like eternity to him to be in this nostalgia setting after Rin finished her plate she stared at Shirou.
"So do you have any Idea what you're involved in?" She asked in a very serious tone Shirou look at her with a blank expression.
"Not a clue." Rin became dumbfounded.
"What kind of Magus are you to summon a servant and not know what you're involved in." She looked at Shirou in annoyance.
"I'm sorry Rin I honestly don't know what I'm involved in." She sighed in frustration
"Alright I'll explain what you're involved in it's called the holy grail war. the holy grail war takes place between seven mages that each summon a servant they fight to the death until there is only one mage and servant then they get the holy grail." Shirou stares at Rin in disbelief she points to Shirou.
"You have been chosen as a master of this war the command seals on your hand and obviously your servant Lancer are proof look at your hand." Shirou looked and he say red markings on his hand in a form of a symbol.
"Those command seals are what bind your servant to you and they give you three absolute orders over your servant." Shirou look at them in disbelief how could people kill each other for something like this Shirou looked at Rin.
"If we are both masters then why didn't you kill me when I was unconscious?" Rin slightly blushed.
"Because it wouldn't be right you didn't know what was going on and you were unconscious. I would never do something so lowly." ya you keep telling yourself that Rin Saber thought in amusement. Shirou walked to the door and looked out side.
"How did my shed get fixed?" Rin looked at him.
"I did while you were unconscious." Shirou looked in amazement.
"Really you can do that."
"Ya of course this is basic stuff."
"It is, because I can't do it." Rin stared at him completely dumbfounded before she opened her mouth.
"What kind of magecraft do you use." Saber asked he saw the opportunity and capitalized on it Shirou looked at Saber for a moment.
"Well I can use reinforcement and projection but I can't use them that well." he said
This made Rin even more dumbfounded this guy isn't even a proper magus and he summoned a servant while Rin was trying to comprehend Saber decided throw the curveball.
"How do you use your magic can you elaborate step by step." Lancer looked at Saber with curiosity trying to figure out Saber. Rin was trying to figure out Saber's motives behind the question.
"Sure I first focus and create a magic circuit... Wait you said create a magic circuit." Rin interrupted Shirou he nodded it's a hit and home run Saber thought. Rin put her hand on shirou chest he blushed.
"What are you doing?" Rin looked at him in a state of shock
"How can that be." she slumped down Shirou looked at her in confusion
"what Rin?" she looked at him in bewilderment.
"You have 27 average natural magic circuits and 5 below average artificial magic circuits." She fell to the ground as if she fainted from the shock. Saber looked at Shirou in surprise well that's definitely different he thought. then he look at Rin whose mind was completely out of order she was sitting in a corner with a dark cloud hanging over her head as she is mumbling what sounded like threats to Shirou.
"Rin are you alright." both Shirou and Saber said in unison in the exact same way Rin cocked her head around to see both Shirou and Saber had the same expression even Lancer looked at both at them Shirou also stared at Saber. Crap will they figure it out he thought. Rin looked at Shirou now getting her thoughts back in check gives him a very pissed off look in one move she grabbed Shirou by the collar of his shirt and started shaking him.
"HOW CAN SOMEONE LIKE YOU MANAGE TO ACCOMPLISH WHAT THE GREATEST MAGUSES HAVEN'T EVEN COME CLOSE TO ACHIEVING!" She yelled at the top of her lungs Saber let out a cough then Rin looked at him with the same pissed look.
"Rin if you want to do such inappropriate things to Shirou I suggest taking it elsewhere." Rin looked then realized the position she was in she was straddling his stomach while holding Shirou practically up to her face when Shirou also realized this they both let out a bright red blush as Rin immediately jumped off of him Saber chuckled as well as Lancer now I see why everyone teased her.
"As if I would do something like that." ya keep telling yourself that Saber thought. Rin stood up.
"Come on Shirou we have to go." Shirou gave her a confused look.
"Where?" she looked at him annoyed
"We have to go to the church and confirm you as a master."
A/N so funny thing i had Arjuna as a heroic spirit I even was making saber as a lancer in this then grand order came out and confirmed them both as actually thing and i'm thinking i called it so yeah