A little Fate challenge when Rin summons the King of Heroes... sort of.

Rin coughed from the dust expelled from her summoning attempt. When it cleared from the air, she looked around.

"Where is he?" she asked herself. Suddenly a loud bang was heard as the house shook. She raced out of the basement and up the stairs to a sitting room. Or at least what once was the sitting room. The items of furniture appeared to have been completely smashed by a massive force from above.

'Clearly a servant, but who-'

She then heard a squeak, quickly recognizing the sound being the refrigerator being opened. "Oh no," she muttered as she ran out of the room. "Don't tell me my servant is a glutton!"

When she arrived at the kitchen, she was surprised when she saw a small figure pushing through the fridge, a cheerful hum mixed with the movement of the food inside.

Refraining herself from marching over and pulling the intruder by his clothes, Rin let out a loud cough. "Ahem."

The shuffling stopped, and the figure came out of the fridge to be revealed as a young boy with short blonde hair and red ruby eyes filled with confusion. He wore an open white-jacket with black rim on the inside and gold cuffs on its short sleeves, white pants held up by a gold belt, gold bracelets, and a gold necklace.

"Oh, sorry Nee-san," the boy said with a polite tone that carried a sense of nobility. "I was trying to find something to eat."

'Is he… no! There must be another explanation!'

"I am Tohsaka Rin, and I wish to know who you are," Rin said with what sophistication she can muster, while inwardly she prayed that the boy was a regular intruder that came in during the crash.

"Oh, that," the boy smiled as he held a hand to his heart. "My name is Gilgamesh of Uruk, of the Archer Class. Are you my master?"

"..." The pig-tailed mage only stared back with an expression of horror.

"Um, Nee-san?"

"WHAT?!"

Kotomine looked up from his scripture. "That feeling," he mused. "That is the sound of immense torment. But from where..."

"Oi, priest," Lancer snarked at the man. "What are you so happy about?"

The priest gave a small smile at the Irish hero. "Nothing you need to worry about, Lancer."

'Yeah right.'

Rin felt like the laughing stock of mages everywhere.

First, she was unable to detect the test set up by her late father that speed up the clocks in her house, thus leading her to summon an Archer instead of a Saber as intended.

Second, instead of a proper heroic spirit, she summoned a child into a war waged by skilled mages and powerful Heroic Spirits.

And third, once she confirmed said child's claim, she found out that she summoned Gilgamesh, the legendary King of Heroes her father once summoned in the previous Grail War, as a child. As in the point before he even completed the adventures told in his namesake epic.

"Technically, I do remember everything that older Gilgamesh did," said boy added while she was frantically rubbing her scalp. When she turned to him he smiled in amusement. "It was easy to guess what you were thinking, Master."

To clarify, Archer could remember in perfect detail the life of his older self. His arrogance as a king, his friendship with Enkidu, his ire with Ishtar, and his search for immortality. The boy was quite horrified of how self-centered his future self is, so he was much grateful to be summoned in his current state.

(And grateful for the sake of his new master. He doesn't know if she and older Gilgamesh could tolerate each other so the latter wouldn't want to kill the former, much cooperate)

Rin took a deep breathe, gathering back the elegance of the Tohsaka family within her. "Sorry about that. I was, surprised at your current state, your highness."

Archer smiled. "You don't have to be so formal, Master. Archer or Gil would be fine."

She smiled back. "It's alright, Archer. Speaking of which, you may call me Rin."

"Alright, Rin-nee-san!"

'Wait for me, nee-san!'

Rin flinched. "Just, just Rin is fine."

Archer frowned but nodded. "Alright then, Rin."

"Well, with that out of the way, let's check your stats." With that, Rin received all the information about her new ally.

Strength: C

Endurance: C

Agility: C

Mana: C

Luck: A

Noble Phantasm: EX

'Average stats, but not exactly terrible,' she thought. 'His Noble Phantasm, on the other hand...'

"Could you explain your abilities, Archer?"

"Of course. My main Noble Phantasm is Gate of Babylon. From there I can summon one of many items from my arsenal. Most of them are prototypes of every Noble Phantasm-"

"Hang on, every Noble Phantasm?"

"Just their prototypes. Along with every treasure imaginable."

"In other words, you can summon a weapon that can counter any other servant. Nice to hear," Rin smiled. Perhaps with her new servant, she might have a chance to win the Grail War.

The next morning, Rin rose from her bed like a zombie from its grave as she struggled to pull herself from the covers. With reluctance, she managed to get herself cleaned and dressed.

Stepping out of her room, she was surprised to see that the living room was now clean. The hole in the ceiling was now repaired and the furniture was upright and fixed.

"Good morning, Rin," Gil said from the sofa as he read a novel (one of the many books Rin's mother used to read to her and her sister when they were kids).

"Did you do this?" she asked in surprise.

Gil nodded, causing the mage to sigh. Despite being her Servant, it felt wrong to have the boy clean up everything by himself, even if he made the mess in the first place.

But before she could say anything, a man wearing a white maintenance uniform and holding a clipboard uniform entered the room.

"Alright, Mr. Uruk," the man said. "Payment has been finalized."

"Thank you, Mido-san," Gil replied cheerfully as he jumped from the chair and walked over. He then handed the cleaner an emerald as big as the man's fist. "Consider this a tip."

Mido grinned. "You're welcome, sir!" with that he quickly headed out of the house.

"Archer…" Rin began, held back rage in her voice.

Gil turned to her, not yet aware of her anger. "Yes, Rin?"

"What was that?"

"A tip for a good job. I was troubled when I learned that modern men do not use gems or gold as common currency. Luckily, it suffices as a tip."

"I mean, why was that man here?"

"Oh," Gil shrugged back "I felt bad about the mess I made when I was summoned, as it was against the policy of a guest, so I sought to fix it. Unfortunately, I did not possess any skills in cleaning, since the servants usually did that. So naturally, I hired professionals to clean up."

"You said that you learned they didn't accept gems. How did you pay?"

"Oh, I simply use some of your money. Took me a while to find it, though."

"How much?"

"About 108,000 yen. Is that bad?"

"..." Rin's face lost its color as she collapsed onto the opposite chair. "Two weeks worth of savings… gone…"

Is this her fate? To win the war but lose all of her money in the end.

"Eh, was it really that much?"

"Yes!" she shouted, glaring daggers at the boy, who was unfazed. "Urg. Listen, Archer, you can't just go using my money without my permission. Next time you want to buy something, ask me first, ok."

"Alright then."

"And you'll be helping me get back what you spent by selling some of those jewels of yours."

"Hai," he said, a little more bored.

Well, she managed to summon a servant that is costing her money. Hopefully, she'll win before she goes bankrupt.

Hours later, the two were standing on a building overlooking the Fuyuki skyline.

"Amazing how much brighter the cities are, " Archer commented, kicking his legs as he sat on an air vent.

"Sure," Rin said casually. "Just remember we're here to locate other servants." She frowned. "Since we're here, I want to know: What's your wish?"

"Pardon?"

"Every servant summoned has some sort of wish when entering the grail war, whether for a wish granted by the Holy Grail or just being in the war itself. So what's yours, King of Heroes?"

Archer chuckled. "I actually have no wish. The truth is, the grail is mine."

Rin raised an eyebrow in disbelief. "Is that so?"

"Well, rather it is my older selves, for he collected all of the world's treasure."

"I doubt a hero from millennia ago manage to collect an artifact created in the 19th century."

Archer shrugged. "True. Perhaps you can say I'm starting my collection early. So what about you, Rin?"

"Same as you, I have no true wish. All that matters is fulfilling my duty as the Tohsaka head."

"It's funny isn't it?" Archer said. "A master and servant with no true wish, only to acquire the grail instead of the power it possesses."

"I don't find it funny," Rin replied. "I just find it as life."

"A dull answer. But, that doesn't make you a dull person. I look forward to fighting alongside you."

Well, maybe the grail might be closer than she thought.

The next night, Rin stood on the roof of the school examining a rune sigil. She placed her hand on it, and it glowed a bright red before fading. "That's the seventh one. Not sure I can stop this blood fort."

"One meant to drain the souls of the school's residence," Archer said through their mind-link. "Clearly for servants to consume to maintain their non-corporal bodies."

"Isn't the mana their master's provide enough?" Rin asked with suspicion.

"Normally yes. But often powerful Noble Phantasms require a great amount of mana to use. It's a needed strategy"

"Don't mention such things again, Archer," Rin said.

"Don't worry, Rin. I won't win this war at the cost of innocents. Besides, most masters who do this are either incompetent or heartless, and you are neither of those things, Rin."

A slight blush covered Rin's face. "Flattery will get you nowhere, your highness. Besides, I am a magus. Being heartless is our nature."

"Sure." Rin could tell the boy hero didn't believe her.

"Just let me erase this and-"

"That'll be a waste," a male voice spoke up. Rin gasped as she turned and saw a smirking blue-haired man in a blue jumpsuit kneeling on a water tower with a red lance over his shoulders. "I rather see what this magecraft will do."

"Did you make this?" Rin questioned.

"Dirty tricks like that are the roles of masters," the man responded. "My kind just fights when they tell us too. Ain't that right," he gazed pass Rin. "my invisible friend."

Rin realized he was looking where Archer was. "So you're a servant then."

"That's right," the Servant said as he got onto his feet and held his lance with one hand.

Rin looked around and saw all four edges of the roof ended with a fence. 'We're in a disadvantage in this small space.'

"Looks like you know a losing fight when you see one," the Servant said. "Probably shouldn't have alerted myself, but I can't help but be curious." He leaped off the water tower towards Rin, who sprinted away from him.

Ducking from the swing of his lance, she began a chant in her mind. 'Es ist Gross. Es ist Klein!" her speed increased as the magic circuits on her legs became visible. 'Vox, Gott es Atlas!' She then jumped straight over the fence and off the roof

"Handle the landing, Archer!" she shouted as the ground came closer to her.

"On it!" he yelled. She was stopped a few feet from the ground before the invisible Archer jumped forward and sent them rolling in the air and across the pavement. When she got up, she sprinted forward after sensing the enemy Servant behind her.

Stopping a few feet away, she turned and saw Archer materializing between her and the enemy.

"Archer!"

"I have this, Rin," the boy said.

"Well, well," Lancer said, eyeing the boy. "Never met a Heroic Spirit so young. What happened to end your life so soon."

"Nothing," Archer smiled. "I lived a long life. I just happened to have been summoned in this state."

"Never heard of such a thing…"

"Archer, can you handle this servant?" Rin said in a serious tone.

"Don't worry, Rin. I should be able to defeat this Lancer."

"Good guess on my class. I'm not too keen on fighting a kid," Lancer said, bracing forward his weapon. "But I'm anything but rude enough to disvalue a willing opponent."

In the church, Kotomine Kirei recalled the previous events, where Rin has introduced him to Emiya Shirou, the adopted son of Emiya Kiritsugu who has now joined the war.

And according to Lancer's report, he is now partnered with the Saber servant King Arthur, just like Kiritsugu. He would be interesting to watch, especially with the boy's survival guilt from the Fuyuki Fire ten years ago that was so obvious to a man like himself.

But as entertaining as that news was, it did not cloak the more, pressing news involving his charge Rin.

"What is it you ask for, Kotomine?" an irritated voice said as his former servant appeared in a pew.

"Gilgamesh," the priest greeted. "I wanted to inform you of two competitors in the Grail War, specifically their servants."

"What matter are mongrels to me?"

"The first is that Saber, just like you, has returned to the Fifth Grail War."

An amused grin came onto Gilgamesh's face. "Saber? So the girl King has returned. It seems I have a new chance to make her my bride."

"And then there is the other. Rin has summoned an Archer servant-"

"Do you even think I care about Tokiomi's daughter?" Gilgamesh snarked.

"He is a young servant with blonde hair, and, according to Lancer, was able to summon weapons similar to your Gate of Babylon."

The king was silent for a few seconds, seeding curiosity in Kotomine. What could bring the arrogant spirit to silence?

"The boy, did he act with a sense of politeness to the dog? Was he always smiling in the fight."

"That's correct," Kotomine frowned. "He is you, is he?"

"My younger self, to be correct," Gilgamesh said. "Even though I am no longer a servant, I didn't think that the grail would allow two versions of the same heroes to co-exist."

"It is not unheard of. The Edelfelt sisters from the Third Grail War were said to each has summoned a version of the same hero as a Saber. Somehow, either the snakeskin fossil wasn't destroyed properly and Rin was able to use it as a catalyst, or she was lucky enough to be compatible with your younger self, whoever he is."

"He is a naive and foolish boy that clings to the ideals of good and evil. He believes in caring for the common folk, and while he does not submit to them, he respects the gods."

"You speak as if he is a separate person."

"He might as well be. I have no true recollection of acting that way," A ferocious smirk crossed the face of the King of Heroes. "I thought the only entertainment was to see Saber lose all of her noble ideals. But meeting this so-called predecessor of mine will be all the more interesting. Especially to see what the future has in store for him."

Omake:

If someone told Shirou that he would stand side by side with a blonde maiden knight, his school's top student, and a blonde-haired boy against a white-haired girl and a massive, dark-skinned giant just after learning from a priest of a great battle over the Holy Grail that caused the fire which left him an orphan ten years ago, he would think that they were joking.

Well, it certainly wasn't funny at this moment.

"So you have summoned your servant, Onii-chan," the girl, Illyasviel von Einzbern, said cheerfully. "Shall we begin our duel, or does the pigtail Tohsaka wish to join in as well."

Rin scowled at the mocking tone of the younger girl, while Saber grasped at her invisible blade. Archer on the other hand-

"I look forward to fighting you, Onee-chan."

To everyone's surprise, Illya let out a loud gasp as her pale white face was flushed with a red that contrasted from her violet jacket, taking a step back in shock. Shirou could have sworn that they were hearts in her eyes now.

Rin turned to her servant, one eyebrow arched in suspicion. "What did you do?"

"I just simply referred to her with the proper honorifics by the local land's customs," Archer replied cheerfully. "I had no idea she would react this way."

"Yeah, right."

"D-don't go calling me that!" Illya shouted. "The only one that even comes closest to the right of calling me that is him!"

And then she pointed to Shirou.

"M-me?!" Shirou gapped. "But I'm older than you!"

Illya huffed. "I am twenty years old, thank you for asking."

"Wait, they made a homunculus in the form of a child?" Rin deadpanned. "What purpose was there for that?"

"Hold on," Saber's eyes widened in what appeared to be surprised. "Are you, are you by any chance Irisviel's daughter?"

Illya smiled. "Interesting. You remember my mother from the Fourth Grail War. How fitting that both Emiya's literally summoned the same Saber servant."

"Both Emiya?" Shirou eyes narrowed. "Are you talking about Kiritsugu? How do you know him?"

Illya shook her head. "That's enough of that," she said, her cold composition returning as quickly as it was lost. "Berserker, kill them all. Especially the males."

"You have to be kidding me," Rin groaned as the massive servant charged towards them.

Well, here it is. Hope this grabs your attention. Got some inspiration from Wernher von Braun's Little King of Heroes and a Dojutsu of Rin summoning Adult Gilgamesh. Also, I really want to see adult and child Gilgamesh face off.