Another half a year had passed. For the residents of Fuyuki City, nothing had been changed by the passage of time across this half of the year. For some individuals, their lives were going well, for others, their lives had continued on their downward trajectory. Life had gone on as normal. Nothing had changed in this time. This was different for one special individual within Fuyuki City.

Shirou Emiya the Student was not currently doing well. Shirou Emiya the Student had been an normal student, albeit withdrawn and mysterious. He had still otherwise been a perfectly successful student being able to attain excellent grades coupled with an acceptable conduct. This was the extent of what most people could find out and saw of Shirou Emiya the Student.

Throughout the past months, this had changed. Shirou Emiya the Student had been less of an exemplary student compared to what he had been before. The cause of this was due to Shirou Emiya the Student having undergone what was an abrupt alteration of his typical behaviors in school throughout these past few months.

It first started with homework assignments. Shirou Emiya the Student always had submitted his homework on time and at an exceptional quality. This had changed. He had ceased submitting homework assignments entirely. This would have been a major issue to the teachers normally but for this term the homework assignments were not graded and were thus not considered a compulsory part of school. It was still preferred by the teachers as a tool to assess a student's progress of course. It was only the most delinquent of students that did not submit their homework.

The only thing that decided a student's grade for that year was a project assignment which had been completed and submitted early by Shirou Emiya the Student several months ago. That had not been the extent of the decline that had befallen Shirou Emiya the Student. Shirou Emiya the Student had also been found sleeping in class. It was obvious that the cause of this was that he had come to school exhausted. Almost to the point of unconsciousness.

For the other instances where Shirou Emiya the Student was currently not sleeping in class, he had obviously been studying something on the thick notebook that he had started to write on in school. It had not been something relevant to the material taught in school and it was quite apparent that it was his own private project that he had decided to work on in class.

Shirou Emiya had not been a good student recently. The teachers had noticed but there had not been a drive to correct this problem. There were measures taken however. This problem had been conveyed and brought up to notice to whom was publicly known as the closest friend of Shirou Emiya the Student. It was assumed that whatever the problem was, it was best to be settled by her.

Shirou Emiya the Friend was not being the best 'friend' at the moment. The how of this state was due to Shirou Emiya the Friend being a tremendous emotional burden at the moment for causing worry to his friend. Said friend had been extremely worried by the actions of Shirou Emiya the Friend across the past months and was currently lamenting herself as the cause for this.

Rin Tohsaka was the aforementioned friend of Shirou Emiya the Friend whom was not being a very good example of a friend at the moment. She had kept a close eye on him since the intimate conversation they had several months back. She had a motive in mind when she had decided to tell him about that low point in her short life.

She had seen the situation for what it was and while she had believed in her friend, she also had a reluctant but also very strong faith in the limitations of humans. Especially the limitations of humans who are currently at the age of twelve. Even if the humans were Magi, they still had limitations. She had believed that the most likely outcome was to be a negative and undesired one for her friend.

She did not believe Shirou Emiya the Son had been prepared for the very likely death of his father. It was one thing to be aware of the possible outcome and try to prevent it, it was another to fully accept the possibility and brace for it. Shirou Emiya the Son had not accepted the possibility of the death of his father nor would he have been prepared for the emotional blow that it would cause.

At that point she had believed that it was a good decision to make her friend, Shirou Emiya the Son aware of the possibility of the death of his father and be prepared emotionally for it. Perhaps is still was a good decision. It had not gone the way that she thought though. What she had expected and what had happened was not the same. What had happened should have been what she should have expected from Shirou Emiya the Individual.

She had expected and preferred that while Shirou would continue his path to try and find the solution to prevent the death of his father, he would also be mentally prepared for the outcome and when the near inevitable possibility came, Shirou Emiya the Individual would come out slightly better mentally and emotionally from the acceptance of the possibility to the situation in advance.

What had happened was that Shirou Emiya the Son had now accepted the possibility of the death of his father. What this acceptance had done was instead heighten his already single-minded determination to affect the outcome of the situation.

It was an immediate change that had fallen onto her friend. She had noticed that something was off immediately. The next day after the conversation, she had met him by the Fuyuki Bridge to travel to school together. This had not changed. The real change was what she had noticed even in her sleep deprived state in the morning.

There was something that had changed in the aura that Shirou Emiya the Individual had given off. His appearance was same as usual. His expressions and the way he carried himself was different. While he had acted largely the same around her, the way he appeared on approach was different.

His shoulders were tighter, his muscles were tense. His eyebrows were more serious. Every aspect of how Shirou Emiya the individual had carried himself was more intense. Beyond such observations that she had made about her friend, she had also noticed that Shirou Emiya had also been tired when he had met up with her in the morning.

There were many things that she had been aware of about her friend. One of the things she had been aware of was the trait of Shirou Emiya that he had not required much sleep. He could sustain and operate himself at a high level with barely any sleep. She had never seen him tired. This was why it had been so surprising when she had seen him tired for the first time.

She wondered what had he done to make him feel exhausted and look exhausted. She had immediately linked the state of her friend to her conversation with him. She had thought that it was a phase, several days of her friend being off before he resumed to normal after processing the revelation.

He would not return to his normal state after a few days. Beyond the ways it had affected her and what she observed, it was also apparent to the outside world beyond their bubble. Shirou Emiya the Student had also changed. It had been a concern for the teachers and as his closest friend, they had informed her but their concerns were at the bottom of her attention at the moment.

The situation had gotten worse as time passed. Rin had stopped teaching Shirou magecraft recently for he had mastered the basics and gotten a good foundation in the main branches of magecraft. This was all Rin had set out to teach him initially. It was with this basic foundation that whatever more Shirou had needed to know within the realms of magecraft, he could find out himself. Furthermore, beyond the basics that she had taught him, Shirou had already known some advanced theory in some departments that were even greater than the extent of her own personal knowledge.

There was little left more for Rin to be able to teach him. What more she knew was too specialized and not of relevance to Shirou. Even had she offered, he would not have taken her offer at this point for he had been occupied with other matters. Teaching Shirou further magecraft was not a thought that had crossed her mind. She had gotten over the temporary slowing in the progress that she had personally suffered in her own magecraft when she first met him and she needed the time to take advantage of her once again rapid progress through what she wanted to achieve in magecraft.

Due to the conclusion of her lessons with Shirou on magecraft, he had stopped coming over to the Tohsaka Mansion for lessons. He had still come over occasionally to refer to the library or books in the basement workshop but the frequency of his visits had fallen greatly. While Rin had not required the attention, it would not be out of place to state that Shirou had been neglecting her as a friend compared to how he was before.

What was the cause of these changes? It was not hard for Rin to deduce the cause. Her friend was an individual of extreme focus. What he was currently doing was neglecting everything else in his life to an extent that he had never done before. The reason of neglect was to make the most efficient use of the limited time that he had.

Rin had thought that her conversation with him was the catalyst for this change. What Shirou had most likely done was feel the pressure to a greater degree of how little time he likely had left. This warranted more time or a more efficient use of the time he had. As such, what time he had used for sleep at home had been regulated to school.

The extra time he had gained when not in school was used up in his quest to find and use the correct magecraft to solve his father's predicament. When Shirou had met with her on the way to school, she had been able to sense less of the magical energy that he normally possessed. While Magi could suppress their own magical energy, the alternative was that Shirou had likely used too much and had drained himself nearly dry on magical energy before traveling to school.

Rin had still been able to sense an adequate amount of magical energy that was enough for Shirou to stay conscious. Not enough for most spells, but given what she knew of her friend, he would force himself to draw more and strain his own magical circuits if he thought it would help in his quest. This was proven when she had felt bursts of magical energy in school.

Obviously, the only Magus in Fuyuki Junior High was Shirou and thus the magical energy could only be produced by him. The bursts of magical energy came during the free periods where students were left with a short period of time without lessons. Most students had used this time to visit the canteen and eat.

Rin had noticed that whenever the current lesson was over and a free period was next, Shirou would always disappear from the class to somewhere else in the school before she could talk to him. She had tried to use her senses to find him but while traces of his magical energy were in the air, he had likely been in a bounded field he had created that would allow him to avoid detection from her.

It was immensely frustrating that she could sense his energy but she had not been able to track him down. Shirou's actions were currently a source of worry for her. She wasn't sure as to the right course of action. His actions were not healthy and were hurting himself but it wasn't as if she would be able to ask him to stop, not that it would be right to do so.

What she wished to do was stage an intervention into the situation and confront him. Even if she did so, she had been unable to think of the correct action beyond that. It was only right for Shirou to follow his quest to its logical conclusion, whatever it was. She was effectively left helpless, forced to look upon her friend as he harmed himself for his objective while not being able to provide any help or stop his actions.

Her interactions with Shirou had become less and less frequent as more time had passed, they still had conversations and he had still acknowledged her existence unlike the rest of the school but aside from her silent show of support that she gave to him, it wasn't right for her to demand more time from him, especially when it would take more out of him to compensate for the time lost.

As weeks passed, she had settled on the actions that she would take on behalf of her friend. Beyond his own bubble, Shirou had not cared much about the outside world. Nevertheless, the outside world would affect him and hinder his quest if the correct measures were not taken. Due to this, Rin had taken it upon herself to cast memory interference spells on the teachers of the school in order for them to overlook Shirou's actions and not try to 'help' him.

For the most part, her only method of helping him had gone fine, although it had been slightly tedious for her to ask the teachers pointed questions once in a while to check if the spell had worn off or to cast the spell again. The only thing of concern was that this had somehow aroused the suspicion of Issei Ryuudou. It appeared that he had some awareness of the supernatural. It was no big deal but she just had to be more careful when doing anything magical in school.

As more time had passed, things had started to settle down. She was resigned to the situation until one day where Shirou had called her at night the day before to not wait for him at the bridge in the morning. She had done as he had told her and had not waited for him. He did not arrive at school on time. She had half expected it when she had first got the call from him but it was still rather alarming for her to not see him at school even later in the day. He was absent. He would continue to be absent for some time to come...

Shirou had been coming to school for the past two weeks. It was a deliberate decision that he had undertaken. He wasn't feeling unwell, there was nothing wrong with him. He just needed more time. He had figured out some time ago that Rin was covering for him and he trusted that in this case she would also help cover his absences.

There were no teachers that had approached him about his declining conduct as a student. He had been surprised but he had also seen some signs that they have had their memory modified. He had been thankful for his friend and apologetic for the trouble but he did have better uses of his time. He only hoped he would be able to repay her when he succeeded.

He had made the decision in advance. He had called Rin and told her not to wait for him in the morning of the first day he had made the decision to forgo school. He had another destination in mind that was not the Fuyuki Bridge. He had woken up at the same time, he had the same morning routine. The only alteration to the program was that he had left the house early after preparing breakfast for Kiritsugu.

The reason for leaving the house early was to not arouse the suspicion of Kiritusugu. The reason to this was that he would be leaving the house with a different attire on. If he had left in his school uniform and had been noticed outside during curriculum time, things could get messy. While he could also do mind alteration spells, he had not possessed much skill in it and it would be an unnecessary hassle.

He had left in simple clothing. Just regular blue jeans and a white shirt. He did still have his scarf on though. While the weather was not hot enough to require a scarf. The scarf that he brought would be beneficial to what he wanted to achieve.

His intense and strenuous practice in his spell had its drawbacks, due to the strain of him often overusing his circuits, he often suffered from nosebleeds or blinding headaches, preventing him from continuing. He had found out a while ago that his scarf had possessed a healing ability. Due to this, he exploited this ability to be able to practice the spell for longer.

Rather than having a peaceful stroll to where he needed to go in the morning, he had decided to run there to safe time. He ran in the opposite direction to where he normally went when he traveled to school in the morning. He went towards the outer limits of the Miyama district and Fuyuki city. He ran on seldomly used paths, the paths he was running on weren't even paved.

It was a small dirt path he was running on, not a paved walkway. It was a path that likely existed centuries ago, when Fuyuki city was still a small dirt village and the Shinto district had still been a forest. Why wasn't this path paved even in the modern age? It was because it led nowhere. Nowhere except the mountain ranges filled with trees that surrounded Fuyuki city.

It had not taken long to get to there. It had taken half an hour and a lot of panting. Shirou was in great physical state but he was still twelve and he covered less distance with his legs that weren't as long as he would like at the moment. He had not used reinforcement or spells that would speed him up when running as while that would have shortened the time needed for him to get here, that would have also been a waste of magical energy.

Shirou placed his hands on his kneecaps as he hunched forward. He was heavily sweating and out of breath at the moment. As he took a moment to rest, he observed his surroundings. As his head was down, the first thing he saw was the ground. It was full of fallen leaves of differing colors. Some were red, some were yellow, some were green, some were a dead brown.

The leaves blanketed the floor of the forest he was in. There was no grass, just the dirt of the ground covered up by leaves, branches and twigs. Shirou straightened his body, feeling slightly less exhausted. He saw that he was deep into the forest. There were trees in all directions, he couldn't even spot which direction was Fuyuki City where he arrived from. The ground was at a slight incline of only a few degrees. He was currently north-west of Fuyuki city, closer to the coast. If he had traveled south, there was no doubt the incline would be more than the middling climb it was currently.

The trees weren't especially tall, a bit more then a dozen meters tall at best. There were a lot of trees densely packed together, perfect for what he needed. Between each tree there was only a gap of a few meters. There would be no sentient life for at least a kilometer in each direction.

Shirou had not traveled into this forest in order to communicate with nature. No. He had an objective he needed to complete by traveling here. He had figured out that in order to undo and defeat the curse on Kiritsugu, one cast by a heroic spirit, he had to have more knowledge about Curses. Not theoretical Knowledge, but rather practical knowledge.

Aside from practical knowledge, he also had no experience with Curses. He needed experience. He opened his magical circuits and projected four daggers. They were simple daggers with a steel hilt and handle. He willed his magical energy into the daggers and threw them upwards. The daggers flew in four directions at the same distance of a dozen meters away from him. The formed a square with him in the middle.

"Set!"

The four daggers impaled into the ground lit up with red magical circles around each dagger. A bright white line of magical energy connected each dagger to the next, linking all four magical circles together and creating a boundary around that small part of the forest.

The boundary defined by the line of magical energy was not a type of bounded field. It was rather a specification. A specification for a system that was meant to define the area of effect of the spell Shirou was about to cast. The spell would not have effect beyond its stated boundaries.

It was for this reason that after linking the magical circles together, Shirou quickly jogged out of the boundary and outside the confines of the magical lines. He did not want to be part of the effects of the spell he was about to cast.

"May the truth foist its burden of significance upon me"

Unlike the first time he had succeeded at this spell, there was no light show appearing after his Aria. He had corrected that problem. As he raised his left hand, it lit up with a white magical circle appearing when he willed it to. The previous magical circles surrounding the four daggers turned white as well. With this gesture, he had linked the confines specified with the daggers to the spell he was about to cast. With but a thought, he manifested the concept of decay onto all living material within the boundaries.

The effects were apparent immediately. The many trees within the boundaries that he had specified started to change in color rapidly, the leaves and branches on the ground also started to decay beyond their previous already decomposing state.

Upon seeing the signs of decay setting in, Shirou disconnected himself from the spell. The effects of the concept he had specified would continue and it would take a maximum of ten minutes for everything within to have decayed completely.

Shirou attempted to undo the effects. Due to him disconnecting himself from the active spell. He had effectively given up control on the spell and thus he would not be able to modify its current state. As such, he had to undo the effects of the spell instead of just cancelling it with a mental command.

It was not hard to undo the effects; it took about as much effort as it did to create the effects. What Shirou had done was to input magical energy onto his active system and undo the effects by casting the concept of nullification upon the previous spell. The singular magical circle on his left hand appeared again and faded upon the countering of the previous spell.

The aim of the experiment was not to know if he could undo a curse. He knew he could. The aim of this part of the experiment was to give him a basic baseline of the effort it took. The magical energy from his circuits required to cast the spell was of a similar amount to the magical energy that it took to nullify the previous spell. This might only be true at such a low expenditure of magical energy though.

The easiest solution to solving his father's condition if he had enough power was to simply cast the concept of nullification upon him. It would nullify the curse and the effects of the curse would be gone. Was the easiest solution the most efficient one as well? Shirou did not have unlimited magical energy after all, he had to go for efficiency rather than ease of use.

While the spell that Shirou had invoked was the concept of decay, the malady affecting his father was a Curse, not such a spell. Although, the most immediate issue at hand was a specific concept involved within his father's problem, decay. That was what was killing his father. The other effects were secondary. This was why he was focusing upon decay.

Sure, while he would like to undo the Curse completely and spare his father from the effects, he was running out of time. He had to be realistic here. He had to be efficient. He had to attack the key problem of the curse, he had to first make sure his father had not succumbed to the curse. There was ample time for the other parts of the curse once he had succeeded at undoing the most important part of it.

It was part of this need of efficiency in his spell casting that he had skipped school to obtain more time to find better methods to help his father. While being able to undo the effects of decay upon a small wood in the forest was good and all, he was still going up against a potential noble phantasm here. A Noble Phantasm would easily be able to obliterate the whole forest.

Shirou had to scale the effects up to more effectively emulate what he was going against. He clenched his fists, he reached out his senses towards the four daggers containing his magical energy that had made up the still active boundary anchors. With a silent command, the daggers decoupled themselves and flew into the air in an arc, once again landing at four different points and creating a new boundary, significantly larger by magnitudes this time.

Shirou had to use more effort this time. He controlled his breathing and drew out more magical energy, a quarter of his maximum output from his magical circuits. He fell deeper within the ocean of mist that he had entered whenever he required more of a concept. This time, instead of just brushing off just a slither of mist from the ocean or even gathering a portion equivalent to a large water tank, he grasped and pulled on what seemed like an entire sea of mist manifesting themselves as an intangible concept of decay.

The white magical circles appeared on both hands this time, and with a greater radiance as they pulsed once brightly before they again faded. Shirou looked around him, it seemed like the entire forest around him, living matter as far as he can see had begun to decay. As he had not yet disconnected himself from the spell, he was immune to its effects unlike the environment beside him.

The next step was a delicate matter. Shirou once again steadied his breathing, keeping it perfectly in sync with the other functions of the body and in tune with the environment before drawing another quarter of the output from his magical circuits. He once again delved into the ocean of mist and drew an equal amount of mist but this time manifesting itself in the concept of nullification before disconnecting himself from the previous spell and manifesting this new spell onto the environment around him. The two actions were done in sync at the same time, this way as long as the counter spell worked, he would not suffer the effects of being in confines of the spell.

The new spell manifested itself differently by producing a wave of energy coming out of him at its core spreading in all directions as it nullified the previous spell. The wave of energy spread for a distance before it hit the confines defined by the daggers and faded into the air.

The effects upon the environment had seemed to be nullified at the moment of the completion of the counter spell. Shirou was about to take a step forward when he fell forward onto the ground in a fit of weakness, catching himself on a single knee before clutching his heart underneath his shirt. He suffered an intense fit of disorientation before the pain disappeared as he spotted just out of the corner of his eye, his scarf pulsing brightly with an outline of magical energy shining along.

Upon orientating himself, he saw that the environment had restarted its progress of decay, the spell of nullification apparently having failed. This time however, he seemed to be included within its effects as he had disconnected himself from the spell. The only thing stopping him from also succumbing to the effects of the spell was the abilities of his scarf.

Now that he had been aware, he could be fine without his scarf as long as he had started to circulate magical energy through his magical circuits as resistance to the spell. It would cost a large amount of magical energy and he would eventually succumb, but he would be fine for the moment. It was with this thought that Shirou was glad he had brought his scarf, both for catching him in the moment of unawareness as well as being a reassurance as to the safety of the situation.

That being said, he had to stop the effects of the previous spell of decay. He did not want to imagine the fallout if an entire forest had been found decayed into nonexistence within a day. He took a deep breath once again and delved into the mist. This time, he took the same amount of mist as well but kept the link open if the spell required more magical energy to take effect.

He used a different concept this time. The previous concept of nullification had not worked. Or rather, it had worked, but not well enough. Shirou had been aware of this possibility when considering the possibilities of using the concept of nullification.

Nullification was to nullify all the effects, as if the previous incident had not happened entirely, there were no negative aftereffects, there was nothing. The incident had not ever happened. To use the concept of Nullification was to make the incident null, it had never happened. This was why Shirou had been caught unaware by the effects of his own spell.

The concept of Nullification imbued within the spell had worked against the concept of Decay onto the forest. However, the concept of nullification aimed to undo all effects within the confines of the spell, as if to undo time itself. Even if the spell had managed to make it seem as if the effects of decay had stopped, and prevented further decay but kept the past damage, the concept of nullification would still have the same result.

To nullify was to make it so as if the incident had not happened, as long as a minuscule presence of decay had still occurred within the confines of the spell, the nullification would undo itself. The continued existence of the concept of decay had still existed, this thoroughly disapproved the concept of making as if the incident had not existed and undone the entire concept of Nullification itself.

This was the problem of using Nullification as a concept. It was an absolute concept, akin to a rule of the universe itself. If it worked, it would work perfectly, undoing all effects, space and time and all fundamental laws of the universe included. If it didn't work, it would be akin as though the concept of Nullification had not appeared entirely. The continued existence of whatever was supposed to be nullified became the antithesis to the concept itself, defeating it entirely and rendering it null.

It was why this time, Shirou had decided to use the most efficient method of what he had learned thus far. This time, he manifested the concept of Sealing upon the confines of the spell. It was like he thought, a wave of energy blasted itself onto the confines of the spell before fading once again but he could see that the spell had worked. He had to make sure however.

Visual confirmation was not enough, Shirou had continued to wait for minutes before deactivating his magical circuits. The spell had worked. The decay had stopped. The effects were still there however, there were minor signs of decay upon the environment but the natural cycle of nature would repair the effects.

The spell of decay had been countered. The effects had stopped. By using the concept of Sealing, he had used even less magical energy than he had thought viable. This had proven something. There was merit as to Shirou's theory.

The concept of Sealing was to complete something. The Concept of decay was to decay within the confines until everything had been decayed completely before resolving the concept. How the concept of Sealing within this circumstance worked was as a specific concept.

To manifest a concept within the World was like making a contract with the universe. The concept would be manifested and it would exist until the concept had been completed or resolved. The key part of specifically choosing the concept of Sealing as a spell to counter had not been as a band aid to seal or stop the problem.

No. If the only aim had been to stop the problem, the concept of decay would have been stopped temporarily but it would still exist and resume the effects once the band aid had disappeared. To just simply stop the problem would be foolish. Shirou had theorized that the most efficient way to defeat a concept was to resolve the concept, to remove its meaning of existence instead of directly putting his might against the original concept.

It was due to this that Shirou had chosen the concept of Sealing. It was meant to provide a resolution towards the concept of decay. What this resolution did was act as an antithesis to signify the completion of the concept of decay and thus end the need for further decay. By ending the need of decay, the current state was all that was needed for the resolution of the concept before the concept had no need for existence entirely.

To use a general concept such as Nullification to encompass everything would require a large amount of magical energy to be successful, to use a direct counter concept such as Reinvigoration against decay would require an equal amount of magical energy to be successful but by using a specific concept such as Sealing to resolve the concept, only a minuscule amount of magical energy would be required.

It was this now proven theory that Shirou was relying on. It was the pinnacle of everything in magecraft that he had learned, his ultimate realization, his Magnum Opus. It was with this efficiency in the use of magical energy that Shirou would be able to undo the Curse that had ailed his father. It was with this revelation that Shirou would be able to overcome the power of a heroic spirit, legend and all. It was with this, that Shirou would be able to succeed in his quest.

Authors Notes:

Time skip of half a year after Rin's conversation with Shirou and the conclusion of their project. We see the effects of the conversation immediately. While Shirou had never had much to care about school, he still was a good student. He neglected school to a degree for his quest but now his conduct devolves into delinquent behavior. The cause of this is his greater desperation towards his quest such that any time that can be spared (Time dedicated to school commitments) will be spared in order for more time to contribute to his quest.

It is due to this behavior that Rin is worried about him. It is her that had ignited this greater degree of desperation in Shirou after all. We find out that while she sympathizes with Shirou, she does have a motive as to having their conversation and sharing her experiences. Her motive seems to have backfired.

Instead of just being more realistic and resigned to the problem and prepared for the outcomes, Shirou just has a greater motivation to solve the problem. However, it is at this stage of Kiritsugu's health that his quest finally takes hold of every single waking moment of his life.

Every part of Shirou changes due to this desperation. Even his general demeanor. When he meets up with Rin in the morning, he lacks sleep, sleep he recovers in school. Rin believes that this is just a temporary phase before he gets better but Shirou never gets better. He just gets more desperate.

Meanwhile, we learn that Shirou's lessons in the foundation of magecraft with Rin have finally ended. This gives the opportunity for less interactions between them. Normally, Shirou would continue to help her, but Shirou decides that he would repay her in greater amounts after he succeeds in saving Kiritsugu. He believes the time is paramount at his moment.

It is part of this need to optimize what time he has that Shirou even risks doing magecraft in school, albeit hidden behind a bounded field. We see Rin's concern as to Shirou health caused by his behavior. She is left in a precarious solution as it is nor her place to ask him to stop, nor would she want to, but she has to watch her dearest friend hurt himself until the conclusion of his quest.

While she laments the lack of interaction between them, she still decides to support Shirou by helping cover for him for that is the extent of what help she thinks she can provide for her friend. Shirou's decline gets worse and worse until he forgoes school entirely until he concludes his quest.

Back to Shirou, we see what he goes through. He is very apologetic for burdening his friend but his quest is still the most important thing at the moment. We see what he does and where he goes when he skips school.

Shirou needs more experience casting his spells with a high energy level so at this stage practicing in his shed just doesn't cut it anymore. We see how he practices as he performs his spells as well as the aim of his experiments. He knows he has to be smart about casting his spells due to going up against what was likely a noble phantasm in the form of a Curse.

He almost suffers harm from getting caught off guard by the spell he had previously cast. The scarf helps him greatly in this time of weakness. He delves into the likely reason why his spell of the concept of Nullification has apparently failed.

The rest is more lore as well as why conceptualization as an Origin is so compelling. Shirou isn't so much bottle necked by his actual abilities as much as he is hindered by how he uses his abilities. The lore given here is a deeper look into the actual use of conceptualization in spells. Conceptualization and concepts are the embodiment of reasons of existence. This is the key to this Magic. It's not about if Shirou can do something or if he has enough magical energy to do something but rather how he decides to do something. Its more about being smart and understanding of his own Origin than any limits.

The only problem left is that understanding increases with time. Fortunately, Shirou has the exact understanding that he needs at the moment.