AN: hey this is maticore and this is my usual announcement saying that I do not own the IP of Fate nor harry potter.

Return of the guardian

The war begins

Time had passed for the small family and both children had started their respective schools. Shirou being a Magus in training was being taught the ways of the newly formed Emiya clan and thus was sent to the local schools so that he could have a modern education. Kiritsugu due to his job as a problem solver for the goblins was found to have a potentially lethal curse upon him. Luckily the curse breakers of his new employers managed to undo the damage it caused, but their further investigation found thousands of different curses upon the site of the grail. It was just luck that he only had as few as he did.

Lastly there was Illya. Due to her heritage a normal school was out of the question, not because she didn't want to go but because the laws of Japan. Whilst magic is not as strictly regulated, that is only because the government had spiked the water with a compulsion potion that causes people to rationalize any such occurrences. The problem with a school was that even with the potion the childes mind being more flexible and willing to accept the strange means that the effectiveness of it is dulled on the young unless it is reinforced with someone they trust essentially subliminally programming them to look the other way.

It is because of this that the Japanese government had set up magical academies for all ages allowing entry at any time. This is to account for discovery of their magic. The majority of the classes in such schools where made up of mundane topics with some magical tacked on at the end. It was structured this way so that all students could choose if they wanted to live either solely in the magical community or in the non-magical and still be productive.

It was due to this that Illya was at Mahoutokoro magical academy when she was hit by a large pulse of prana. This pulse knocked the girl unconcious.

Xxxxx

At the same time the Ley lines of Fuyuki city had gathered a extraordinary amount of energy. This was the sign of the beginning of a ritual. The most powerful ritual ever created. So as the ritual had reached its 'critical mass' it sent out a Identification pulse to find suitable masters. Upon locating them. It checked to see if there was any problems with the ritual. During the check it found a blip but could not identify what it was. Not happy with this the ritual sent out another pulse to identify the problem. It failed. It decided to resort to its fail safe. Ruler.

Xxxxx

The war had begun. The masters had been chosen. The servants would be summoned soon. But what no one understood was why young Illya Brunestud, a young eleven year old had suddenly collapsed.

Illya's mind scape

Slowly and groggily she lifted herself off the ground. She felt like she had been hit by Aunty Altrouge or Mommy Mordred (please don't tell her I said that). At that thought she had to smirk at that . Most people complain about being hit by buses, not her, nope her family of super powered bad asses put a bus to shame!

So here she was sitting on the ground in what appeared to be a field. Looking around she couldn't help but be awed. There were what looked like an endless amount of swords in the ground. Some she could remember from dreams or she had projected on instinct during her magus training. Others she had never seen.

"I guess you like my collection then?" said a beautiful voice that came from behind her. This caused her to 'eep' and dive behind what looked like a slab of granite. Slowly she peeked out. She couldn't help but blush at the person she saw.

She saw a woman who was between 16-18 years old with silver/white hair tied up in a bun held together with two small throwing knives. She had startlingly red eyes. She wore what looked like kevlar armour that left her stomach exposed but covered most vital organs, she also had a skirt over a set of shorts allowing her maximum movement.

She also seemed to where some sort of red mantle. Overall she looked elegant yet rough.

"So you are the one I am part of?" said the woman her sharp eyes surveying Illya as she had been surveying the woman.

"Er what do you mean?" Illya asked she really had no idea what was going on.

"Well you see there was this woman called Yuuko Ichihara. Who came to me with an offer you see she is known as the space time witch. And despite my being a heroic spirit I was in a no win situation where my soul would be destroyed. She offered to give me a chance to help one more person before I passed."

Illya could only stare at the beautiful woman in front of her. Wondering what she meant she tilted her head in wonderment.

The woman approaches Illya with her hand extended " It is time for me to full fill my purpose here. You have been healed from the damage that the curse caused you but a person cannot have two souls, or two minds in their body without causing irreversible harm" The woman explained

"Now that the grail war has started again it has given us the opportunity to solve that problem. So will you Illya brunestud allow me Archerko another version of yourself to join with you?" asked the woman … Archerko. Much to the shock of Illya.

"And what would happen to me, to us, if we went through with this merger?" Illya asked hesitantly not quite sure if she wanted to know. All she knew for sure is that she didn't like the sound of 'damage to her soul' that could be caused if she didn't.

"well little sister" smirked the teen at the twitch that she caused with those words. " since we both have the same screwed up duel origins of aegis and death and our elements being life

and destruction. Our capability to use both protective and destructive magics/magecraft is near perfect. Due to this we actually have a better affinity than dear shirou with noble phantasms as we can draw their full potential out." Archerko said with clear pride.

"so in essence you will get access to my armoury and knowledge. That is not to say that you will be perfect straight away might have the instruction manual on my skills but you have never used them so you will need to practice under stand little sis?" Archerko said seriously looking Illya straight in the eye till she received a nod.

"Okay now you have a decision do you want to go through with this? It will hurt... a lot." she said seriously.

At that Illya just looked at her deadpan " I don't know if you have seen my memories but mummies sparring matches hurt... a lot. Pain I can deal with. Damage to my soul I will take a pass." responded the little girl getting a giggle from the Eldar as she had met a version of Mordred and knew just how brutal she could be in a fight.

"well let us begin then." and with that the immense number of magic circuits that inhabited their arms lit up as the trans fer began. Unseen to the two females the circuit pattern started to manifest in the sky above them moving from behind Archerko and tracing the intricate lines and patterns across the dull orange sky above the battlefield of swords. The further the transfer progressed the closer to the blue sky which inhabited the area behind Illya.

Meanwhile this was happening Archerko was slowly starting to glow and disintegrate into flecs of prana as her purpose had been served. She had supported and healed the soul that she was place there to heal and now she had completed her one wish that Yuko had granted her which was to have a legacy. To pass on her knowledge and legend she just didn't expect it to be unto herself. The universe had a screwed up sense of humour. Or should she just blame zelretch again?

Either way it was time to rest.

Medical rooms

Mahoutokoro

It had been a day since young Illya had been brought into the ward and the matron was both irritated and upset. She could tell that there was something going on within the childes mind going by the extremely large amount or eye movement that was happening. On a normal child she would have used legilimency to gently enter the childes mind to see if she could help heal or stear the mind in the right direction. It was what legilimency was created for to help people with mental trauma.

The problem in this childes case according to her file is that not only was she raised in close proximity to one of the sisters Brunestud but she is also actually also her descendant. While this gives her a more efficient mind it also makes it more treacherous to enter unprepared. Secondly there is a note about her having a sorcery trait (described by the local magus she has the possibility to learn the third magic as she has already begun to unconsciously tap the surface of its potential (her familiar/servant is the example)).

To say that this was shocking was a understatement. So here she was monitoring her condition when what looked like markings in the shape of a roaring dragon appeared on her shoulder. Running a test there where fourteen separate marks in total. And they where flooding her body with what looked like pure magic.

Following the magic with her scan she saw that it was maximizing the efficiency of everything it reached as much as it could. It was essentially making Illyas body stronger than it should physically be that was when she noticed the young girl starting to grow.

Apparently the magic's had decided that it was a waste of time to maximize the efficiency of her current body as she was just too small to make use of it properly. So to allow her the best use of adjustments that where done it had decided to give her the optimum age.

Standing there and feeling completely useless as their was nothing she could do to stop this, nothing she could do to reverse it. All she could do is watch as one of her charges where essentially modified by what could only be described as unknown magic's bit at the same time she knew exactly where the magic came from it came directly from a ley line!

Once what could only be described as a growth spurt was over the the matron could only watch over the girl as she and her magic get used to her new body and prey that it doesn't effect the poor girls mind too badly.

Emiya residence

Shirou Emiya was having a terrible, terrible day. First he had found out that his child hood friend was being abused by her brother, to what extent he wasn't sure but he knew she was and it pissed him off to no extent.

So to calm himself down after school he had decided to help out with his old club the archery club. Illya had always nagged at him to go back to the club if only for the social aspect rather than the competition but he just couldn't bring himself to he didn't know why.

Once he had finished cleaning up the Dojo in which he had been assigned. He started heading home only to on the way see what could only be described as mortal combat between two warriors of great skill. Looking at them he couldn't help but admire their blades being an incarnation he could see the peerless quality in their craftsmanship. It was then that he remembered what his father had said.

He had said that the holy grail war was coming around again and that to stay safe he had to stay as far from the fighting as possible. Otherwise he might get dragged in by accident. So with that he turned and started to head away only to hear a stone he had accidentally kick hit the fence. The loud rattle echoed throughout the field in which the two combatants where fighting.

Shirou didn't need to be told what to do he just ran applying a small but safe amount of reinforcement to allow for more speed he only started to slow when he thought he was safe. Unfortunately for him he ran straight into the barbed end of a spear.

He didn't know what happened next apart from collapsing but when he came to he was alone with only a crimson gem next to him. So with the gem in his pocket he made his way back to the clan home. Which upon arrival he found empty he wasn't to surprised at this. His dad had been on a job all week but should be back soon and their aunty Altrouge only really came round when Illya needed something or she felt like it. The other member of their family Mordred had went to collect Illya from school It was the last day of her school so Mordred was off to collect the girl.

So the house was empty when shirou collapsed through the front door reflecting on how terrible the day had been.

He did not realise that the day was not yet over. So their Shirou lay cursing his luck and going through his day in his mind only to hear the wards alert. Immediately his eyes flew open only to see a crimson spear on course towards his face. Diving out of the way he grabbed the first thing he could in thought of defence.

What he grabbed admittidley was one of the most stupid things he could but his life was on the line and he wasn't exactly thinking straight as he picked up a roll of paper and reinforced it making it as strong as possible.

Shirou would never again complain about being able to do the reinforcement mystery as if he survived this night it would be entirely owed to that low level spell. Even if it is only to give him a shield or to dodge.

Eventually he was cornered by the mystery Spearman dressed in a blue jumpsuit inside the outhouse. He had no more options. It was literally his last stand. So picking up a pipe and reinforcing it he decided he would face this man Face to face rather than hide.

It was at that moment a circle that he didn't know was carved into the floor of the out house lit up like it was guy Fawkes and from within came... Illya? No it wasn't his sister. It was a woman who looked remarkably similar to both Illya and Mordred the two had always been so similar they could have been sisters. That just leaves the question who was this person in front of him?

Almost immediately after being summoned the woman literally launched herself into battle using almost the identical technique as Mordred. This caused a raised eyebrow from Shirou.

The battle was spectacular despite not being able to see her sword. The obvious skill level of the two opponents was clear dodging and weaving between each others blows with apparent otherworldly skill that only the heroes of legend were said to have. The dual only came to an end when one of the opponents announced himself as Cu chullan Ireland child of light. And then took a strange stance.

All of a sudden Prana started to literally pour off of his spear. It was then that he jumped into the air and launched the weapon at a considerable speed towards the swords-woman. Who surprisingly somehow managed to block it. But to every ones surprise she was still somehow pierced though her shoulder by the weapon.

It was then that he remembered the information he pulled bout the spear using his abilities as an incarnation. Gae Bulg, a cursed weapon that can rewrite causality to ensure it always hits its target. A truly frightening weapon.

It was at this point that 'Lancers master decided enough was enough and recalled him causing the warrior to grumble and moan about cowards. While he jumped onto the nearest roof before he ran off into the distance.

It was at that point that Saber as she requested to be called sensed another servant and moved to intercept. Running afterwards he saw one of the last people he wanted to see in this crap. Rin Tohsaka. The girl was an orphan and due to her dubious childhood, didn't really know how to interact with people so from what shirou could see she hid herself behind a mask that much that she was getting very close to developing a multiple personality disorder.

But here she was with her own servant facing off against sabre. This was the perfect chance for him to interrogate her for information about this crap. Hopefully she knows something. Just as he was about to say something a voice interrupted him...

xxxxx

earlier that day

xxxxx

Illya had awoken from her slumber In the medical wing to find her mommy asleep in the chair next to her bed. She looked absolutely adorable. Illya had always thought that. When she relaxed enough to actually enjoy herself or when she was asleep she looked just like the sixteen year old girl that she was. Illya would always curse morganna for ruining her mommies life.

Getting up out of bed she felt out of balance, as if the proportions of everything where wrong. Luckily she had been placed within one of the private rooms. So moving towards the mirror she couldn't help but gasp. The person standing before her was not herself, it couldn't be. Slowly she started to make different actions only to see them mirrored.

Slowly looking over herself she noticed that her body was about sixteen and was well attractive. She was just lucky that the merger between her two selves had aged her mental faculties. Looking at herself she could only describe her new body as petite. She was about five foot two inches. Her bust and waist were small but noticeable but the most striking features of her new look was her long flowing golden hair and deeply penetrating eyes. Those eyes that held a slight glow in their core that had always been described by people as if she was looking into peoples souls.

Looking around for something to wear as she was taller and more filled out than she was. She noticed a bag with a note. Approaching it suspiciously she plucked up the note and scanning it with her skill in 'structural analysis' to find that there where no prana traces just ink.

So she proceeded in opening and reading the letter.

Dear Illya/

My Dear little Illya if you are reading this note then the worst possible occurrence has come to pass. Your father might be more trusting than I but I have always been one For back-up plans It is because of that that when being sorted into houses at Hogwarts I was supposed to be sorted into slytherin (shhh don't tell your father he would loose his mind).

Anyway I enchanted this letter my darling daughter to appear if several conditions are met. The first is if both myself and you father are dead. In which I am so so sorry my baby girl we so wished to be a happy family and gladly gave our everything for you where our world from the moment we learned of you.

The second condition was that the advanced glamour that we placed on you was not lifted. This is a continuation of the first. When you were born darling our country was at a state of civil war. We were very close to just leaving the country to ensure your safety. While we where deciding what to do we knew that as a little girl you would be vulnerable to attacks of many different deplorable kinds. To prevent this we hid your birth and when people found out you where under a glamour charm I learned during my time working as a unspeakable. It is a Mix of charm and transfiguration. Thus we hid you in plain sight as a young baby boy by the name of Harrison potter. If this charm has not been released sweety it now will be.

The final condition that we set was when the damage caused by the curse was repaired. Now sweety this was the most difficult for us. Understand that during the war I had been hit with a infertility curse. A curse designed for men meaning it didn't work properly. So while for a while I couldn't have children I was able to bear you but the curse had caused you sweetheart some injury.

It was then that a old man helped us. I was desperate to be able to have a child. I wanted to be a mother. I am not sure how or what he did. He explained it as 'reinforcing' your soul.

My darling daughter despite the lengths I went to ensure I am able to hold you in my arms. I can sincerely say I will be glad for every second I have with you the way you smile at me with you big green doe eyes.

I sincerely hope this letter is never delivered but if it is just know that we will always love you sweetheart both me and your father.

Love/

Lilly potter.

Illya throughout reading the letter couldn't help but cry at the fact that she now had a letter from her mother but she had to giggle, her mother was just a little scatter brained when writing just like herself. It made her feel …. closer some how.

Looking in the bag there was a note

A gift from your self to you./ Z

She knew immediately who that was. Uncle Zelretch never did anything simple. So taking the clothes out of the bag she noticed that it was the same outfit her other self was wearing. From the kevlar body armour right down to the fingerless gloves.

Getting changed into her new clothes (after thoroughly checking them for traps and other possible tricks, this is her uncle Zelretch she has had enough exposure to his … proclivities to know exactly what he is like.)and while waiting for the approval to leave the hospital wing she started to use one of the magics she had been taught in her younger years, a magic that does not require the use of a wand.

Oclumency, the art of organising and protecting ones mind. This is a difficult magic to start especially once older but with the mental flexibility of a child it makes the learning of such a skill much easier, It is for this reason that the government of magical japan made the learning of this skill mandatory for its children both to protect its childrens minds and to help their learning as with a organised mind the speed at which the children absorb information rises drastically.

So it was through the use of this skill that Illya was using to go through the newly added memories and skills. And sorting them into their appropriate places. It didn't take long until she was yanked out of her meditations by the sound of the doctor checking her over at which she was given a very reluctant release.

Xxxxx

just before the summoning

xxxxx

Illya had a bad feeling! She had had one for most of the day. She was planning on spending her time practising her new abilities don't get her wrong she knew she could use them but no where near as well as her other self could.

She would have been Practising and sparing with Mordred but this feeling that something horrible was about to happen just wouldn't leave. So here they were they were walking along the streets towards their home hoping that nothing to bad had gone wrong. They knew that kiritsugu was away on a job so that only left shirou at home.

Big brother shirou. Don't get her wrong she loved her big brother she really did but she also knew that he had mental problems. Not in the case of that he was insane no. he had a bad case of survivors guilt. It had been subtle at first but the signs had been there small things. Recently the extreme selflessness and disregard of personal safety that had shown up where what had confirmed it to her and kiritsugu.

They had both started to try and do something to counter it, hopefully.

Illya really could not say that she was surprised when she arrived home to find two servants about to destroy the road outside her house. Mordred was about to jump in and join the fray until she felt a rising sense of dread coming from beside her. Looking at her little master she could only see a aura similar to that of Altruge Brunestud's rising off of her. Considering that the girl is her descendant that shouldn't be a surprise.

The only outward sign (apart from the dominating aura she is giving off) that she is pissed is that a single pristine eyebrow was twitching at a faster rate as she watched. And boy could Mordred understand why. First was the masters, It was that tohsaka girl and shirou and clearly shirou had no clue what was happening but the basics (did the boy seriously not read any of the information their father give them?) And that was not even the end of it ohh no.

The two servants just made it worse. One was obviously shirou. She had seen his magic in action enough to know what it looked like anywhere. The other though looked like Mordred and since it wasn't she would say that it was her father there for she was going to have fun teasing her grandfather ohh yes she was.

Approaching the group putting as much regality as she could into her bearing from all her lessons about being the head of a house from her aunty and Mother. While she approached her mother summoned her armour and sword just in case.

"WOULD SOME ONE EXPLAIN WHAT YOU ARE DOING? HMM?" she demanded of them as everything came to a screeching halt as they just stared at her.

Sighing god this was going to be a long night!