Disclaimer: First Chapter
Story Start!

"So, she has not summoned her servant yet... and now only Archer and Saber are left."

Naruto had broken into the Tohsaka residence while Rin Tohsaka was at school, and he walked around her family home with Shuten. Having an assassin as a servant certainly was useful for doing this kind of work at the very least. The Caster Servant had been summoned not too long ago by a master who lived out of the city, and it had been confirmed with the Priest that the war was almost started.

Naruto was looking at her prep work.

No catalyst.

Rin was trying to summon without a catalyst at all, meaning that either the summoning would not work, or the nearest object that could be a catalyst would be unknowingly used as a catalyst instead.

"Shuten... hand me the box."

"Sure thing Sweetie."

Naruto grinned as he opened up a floorboard underneath the summoning circle that Rin had set up, and he took the box that Shuten had took out of her jacket for him. He opened the box, and inside of the box was a replica of a gun.

"Now, Rin has her Catalyst for her summoning... lucky her... a replica it might be, but this should be good enough of a catalyst to ensure that she gets herself a nice servant." Naruto stated as he showed off the gun in his hand.

A Colt M1877 Double Action Revolver.

Easy to get your hands on in any antique or replica gun shop, and since replica guns were extremely popular in this nation, it was no hard feat for him to get his hands on this exact replica in Fuyuki. Since he figured out Rin had no summoned anything yet, he would enjoy ensuring that he fought an enemy that he knew would be useful to him that he also knew that Shuten would have no issues at all defeating.

"Seems a waste... she could have something powerful... this seems quite dastardly." Shuten ran her finger along the edge of the revolver in his hands. Naruto paused and thought it over, before he thought it over.

"She will summon a weak servant this way... but I might have to ally with her..." Naruto would have one weak enemy to deal with, but if he ever needed a strong ally, then this would come back to bite him in the ass eventually. Rin was a school girl, and he was sure that if it came down to it, he could cut her hand off and take her command spells away from her by force if needed. If she summoned a servant that was too strong for Shuten to deal with, then there were other options available to him.

Naruto placed the revolver underneath the floorboard and placed it back where it belonged, so that the revolver was completely hidden.

Shuten smiled.

This was so entertaining!

"In the end, she will become an enemy eventually. If the Priest IS a Master, this his servant will be Cu... and I can pretty much promise at this point that Rider Medusa belongs to a Matou. Caster was summoned recently, and that leaves Berserker to Illya... with this, Rin WILL summon an Archer servant... leaving Saber to the last remaining Master." Naruto decided that he was going to allow whatever happened to happen after this point. He didn't even have a single clue on who the last Master was suppose to be, since there were many suspects that it could be.

Too many suspects to make a plan for all of them.

Naruto stood up and he took a handful of paper tags out of his pockets, before he started to put them all around the room, and then he turned them invisible with more tags. Shuten watched with amusement.

"So, who will this gun summon for her?"

"If it works, it will summon one of the most famous outlaws of all time... but a modern day legend without mystic powers... easy enough to handle." Naruto told her. He didn't have all of the money the other people had to get great relics. He used his blood because his blood had been capable of being a catalyst, though he made a mistake in pouring his blood into a red sake cup. "William Henry McCarty Junior."

Shuten raised an eyebrow.

"Who?"

"Exactly... even with the Grail giving you knowledge, the information still escapes you. He was famous, and his skills with this exact gun earned the gun the nickname the Thunderer. You can easily take him down... unless Rin gets a stronger catalyst and summons somebody else." Naruto finished his prep work around the room.

Shuten laughed.

"You truly are dangerous! If she summons something I can't deal with, you're going to blow up her house with her in it... you will make it rain her blood." Shuten couldn't help but drape her body over his shoulders, hanging off of him as she licked his neck. "Sweetie... I am glad that your delicious blood summoned me... I was never this entertained before, even when I was alive." Shuten couldn't imagine being summoned by somebody more her type than this guy.

He was making plans.

Then he had plans that would only be used if his plans failed.

"I'm not that cruel... my plan isn't what you think it is. Though, I do plan to blow up her house if worse comes to worse." Naruto stood up without any troubles. Shuten barely had any weight to him, and her breath smelled intoxicatingly fruity. Where she was right now, he could smell the sweet scent that she had flowing around her.

It was time for them to leave.

-Days Later-

Naruto frowned.

He was staring at a piece of paper.

"Seems your plan failed... she didn't summon the guy you wanted her to summon." Shuten looked at the figure on the piece of paper, and for the life of him he could not figure out who this hero was. His clothes did not belong to any era that he knew of.

Naruto thought.

"... Can heroes be summoned from the future?"

His clothes did not belong to any era in the past, but if they belonged to the future, then it would make sense. It also meant that there would be no record of the man for him to use as a reference either. He would be a weak hero, but he would also be a threat if only because there was no information on him at all. He would not get his power boosted by his fame, but he would have no weakness that they could learn and abuse.

"Ufufufu... and what makes you think that?"

"His clothes... nobody wears clothes like that in history... they are almost like modern day clothes." Naruto used his computer to look up fashions during the most modern day periods possible. He found nothing quite like the man that Rin summoned. "... if he isn't from the past, he has to be from the future... that means something in Rin's possession could serve as a catalyst..." Naruto hummed in thought, speaking to himself.

Somebody close to Rin, or somebody that Rin would form a bond with, strong enough that the person she summoned would answer her calls. Naruto used all of the small context clues.

Shuten just watched the gears in his head.

"... Shuten... has Rin had any extended contact, or shown any interest in any boy with a similar facial structure to this?" Naruto showed her the picture.

He had Shuten follow Rin for 2 days.

"Ah... I can't seem to remember... was there somebody like that?" Shuten teased him, clearly indicating that she knew the answer. She playfully sat in his lap while he worked, and she rubbed his chin with his palm. "... there was a handsome young boy... in her grade even... but he had red hair and his skin was not so dark." Shuten relented with the answer.

Naruto leaned back in thought.

"Name?"

"I believe it was Shirou... Emiya... she seemed to watch over him from a distance."

"... This guy she summoned must be Emiya from the future then. That means he is practiced in magecraft." Naruto spoke under his breath.

"That seems like a stretch Sweetie."

"Is it?" Naruto asked as he looked at the computer. "For her to summon him to this time period, she had to have a connection to him during this present day... she is single and does not hang out with anyone. Mages tend to not hang out with regular people, and Emiya is the last name of a man from the previous Grail War... so the chances are that in the near future Rin develops a relationship with him at around this time period... during the Holy Grail war... meaning that Rin or something she carries with her was her catalyst." Naruto used every single small clue that he could see to put together the identity of the hero she summoned.

Naruto took his pencil and the paper with the hero on it, before he erased the hairline. He then started to draw a different hairstyle, a more youthful hairstyle for the man.

"Ah... that is the boy." Shuten realized that Naruto was closer than she realized.

"So, Rin summoned a future Shirou Emiya... do you have any info on this Emiya?" Naruto asked Shuten.

She shook her head.

He told her to follow Rin, not Emiya, so she followed Rin around for a few days. She had no reason to stalk a boy who she was not ordered to follow. The kid seemed boring for the most part as well, so she had no intention on following him.

"No, I don't Sweetie... and I'll kill him if you ask me to follow him... that boy has a very... boring personality." Shuten showed her more difficult side to him, and he sighed.

He wasn't going to waste a command spell on this.

"Fine... the fact is that even killing Emiya won't get rid of the servant. The fact that servant exists at all means that there exists multiple timelines... so killing Emiya won't get rid of future Emiya." Naruto didn't see a reason for them to target Emiya anyway. "... wait... they form..." Naruto narrowed his eyes.

His eyes widened and he jumped up in excitement.

Shuten was tossed to the ground.

"Sweetie, that was quite... rude."

"Emiya is the last Master! That means HE summons the Saber servant, and since his father summoned King Arthur in the last war, it means they have a relic related to King Arthur... maybe a shard of the Round Table... so there is a chance he can summon ANY of the knights of the round table..." Naruto started to pace back and forth.

Emiya survived the Holy Grail war in at least one timeline.

Rin summoned him back to the present time, meaning that Emiya survived a grail was with a powerful enough servant to beat the likes of Medusa and possibly Cu Chulainn as well. That limited down the servants that could be summoned.

"... Mordred, Gawain, and King Arthur... Mordred kills King Arthur, and is known for treason... so it isn't likely going to be Mordred summoned... otherwise Rin would not have been willing to work with Emiya and they wouldn't bond with each other enough for her to summon him." Naruto narrowed down the next possible servant to just 2 potential servants that Emiya could possibly summon that would fit. "... no... Tristan could be summoned as well... ALL of the Knights could be summoned except for Mordred." Naruto extended the possibility that it was more than just the 2 he picked.

Right, if Emiya formed a bond with Rin, that meant the two of them worked together during this Holy Grail war. That meant the servant he summoned did not NEED to be extremely powerful, it just needed to be strong enough for Emiya to survive while Rin or Emiya got the Holy Grail.

Naruto smiled and sat down.

"Fuck it... I could be way off... I'm going off the assumption that he will use the same catalyst his father used. For all I know, he might have his own catalyst." Naruto relented and gave his brain a rest.

"So, we kill Emiya... and the Grail will pick a different Master?"

"... I didn't even think of that." Naruto muttered as he thought of that. He was overlooking a very clear solution to the problem of Emiya summoning a powerful servant.

Force the Grail to select a different person to be a Master.

Naruto frowned.

"We will Emiya... right?" Shuten whispered to him, and her words were tempting.

"That... would be a good idea... we can guess he will summon a strong servant. Still... the fact is we can somewhat guess what he will summon, and then look up weaknesses... if we kill him... who fucking knows what the replacement will summon." Naruto reasoned that there was no reason to kill Emiya.

Shuten just smiled.

"Sweetie... are you secretely... a big softie?" Shuten teased him further.

It seemed he just didn't want to kill an innocent kid to her.

She was fine with that though.

It was more fun this way.

Chapter End!
Please Leave Me Lots of Nice Long Reviews, But No Flames Please!