Ryunosuke Yusheng, an innocent murderer, is unusually sensitive to the truth and falsehood of death, a crazy performance artist, wants to understand death, is proficient in death, the more people he kills, the deeper his understanding of life, he believes that it is "something that produces benefits", so he has this belief to commit serial murders all over the country. Most of the bodies in the murders he committed have their real identities still on the missing list, and the corpses have been handled very well. On an opportunity to try a new way of killing, he inadvertently summons a caster and becomes his master.

Although Ryunosuke commits crimes everywhere, he has his own job, and he is never interested in the victim's money, and he earns money by himself during the day. A perverted murderer who seems to have moral integrity, but before he summoned CASTER, he was just a psychopathic ordinary person, just an ordinary person, an ordinary person physically, even if he has the qualifications of a magician and can summon heroic spirits, but he has not been trained in a magic circuit, he is just an ordinary person through and through, just like the current situation, after finding out that Ryunosuke Yusheng worked in an ordinary convenience store, This deeply hidden perverted murderer was knocked unconscious by Chen Yu in the first shot, and then taken to the room where the war squad was. As for why he wanted to arrest Ryunosuke Yusheng, in fact, after knowing that Ryunosuke Yusheng hadn't summoned the caster yet, Ning Xiangwen had a bold plan, that is, to replace Ryunosuke Yusheng as the summoner chosen by the Holy Grail, and for the members of the Fire Squad, he was more eager for the Holy Grail than anyone else! After all, if you don't get the Holy Grail, you're dead. However, the next thing to do is the key to deciding whether or not he can replace Ryunosuke Yusheng as the summoner, and the most basic condition to become the chosen one of the Holy Grail is to have a magic circuit. The source of magic that all magicians in this world are born with.

A simulated nerve held in the body of a magician. Qualifications as a magician. The path that transforms life force into magic is the path that is closely connected to the foundation and the grand magic.

The magic is divided into large sources that fill the world, and small sources that are born in living beings. If you want to divide the big source into the small source, it goes without saying that the big source is better than the small source. The power level of the small source magic power made by a human is different from the big source magic power that fills the world. No matter what kind of magic it is, the magic of using Dayuan can easily override the magic used by individuals. Because of this, good magicians are skilled in techniques that draw magic from the world. It's similar to a filter, where the magician uses his body as a conversion circuit, drawing magic from the outside world and making it a magic that can be used by humans. This conversion circuit, which magicians call a magic circuit.

Normally, it acts as a nerve, but the core point is connected to other points to form multiple divergence points. The pathways of these divergent points are connected to the synapse-like substance in the brain, and the core is absolutely unchanged. Strictly speaking, these cores are called magic circuits.

As long as there is a magic circuit, it has the anti-magic power that can bounce off hypnosis, spells, and other interference magic.

If an individual's mana runs out, it will take time for the magic circuit to recover, and conversely, without the magic circuit, mana cannot be generated.

Magicians create a transformation circuit in their own bodies, drawing magic from the outside world and creating magic that can be used by humans. [ This conversion circuit is the magic circuit.] It is an organ used by magicians to transform life force into magical power. It's something like a nerve, and you can't use magic without it. (In the 4th Holy Grail War, Kiritsugu and Emiya Kiritsugu used the seal inherited from his father, Kimasa Hinamine, as a source of magic in the duel at the National Hall.)

The magician's unique internal simulation nerve is a circuit that transforms life force into magic, and as a base, it is also a path to connect the great magic style, and the circuit connecting the spirit and matter is a simulated mystery held in the magician's body. There are two main functions. The generation of magic power, and the way to the magic foundation that is engraved in the world. Magicians use magic circuits to create magic power, and use magic power to push the magic base to perform magic. When the magic circuit is functional, the human flesh is accompanied by corresponding suffering.

Magic circuits are born to determine the number and will not increase due to external factors. Because it is a very rare thing, the magician accumulates several generations of blood, so that the children and grandchildren who are born have a body that is more suitable for magic, and the family that is overdone is like doing breed improvement, increasing the magic circuit of giving birth to children

Of course, there are exceptions, such as Shirou Emiya in "Fate", which is a special case of 27 circuits from ordinary people's families.

Normally, the circuit is only opened once at the beginning, and then it usually lurks inside the body, and can be activated by an imaginary switch when needed, so that it can circulate magic and function as a magic circuit.

However, the innate nature of the magic circuit is not absolute, the Kiriki inkstone can use the marker worm to form the magic circuit of the human body, and the Einzberen family can also use alchemy to create artificial humans with magic circuits, and the alchemy possessed by the war squad seems to be similar to the alchemy possessed by the Einzberen family. Then Ning Xiangwen's idea has the possibility of being realized, so Ning Xiangwen needs a reference, a reference for the human body with a magic circuit. And this best candidate is undoubtedly Ryunosuke Yusheng, who is now lying unconscious on the ground. What Ning Xiangwen has to do now is to discover the difference between Yusheng Ryunosuke's body and ordinary people in the shortest possible time, and for this reason, the other three members of the war squad under the command of Ning Xiangwen used alchemy to create except for a human perspective scanner according to the drawings of the human perspective scanner given by Skynet.

Ning Xiangwen also asked the Terminator-Skynet robot to hack into the hospital's database from the Internet and obtain the body data of ordinary people in this world. Everything was ready, and the unconscious Yusheng Ryunosuke was stuffed into the scanner, and then it didn't take long for a detailed data about Yusheng Ryunosuke's body to appear on the screen of the scanner, and then Skynet Auxiliary Brain compared Yusheng Ryunosuke's body data with the body data of thousands of ordinary people, and sure enough, there was a difference. There are more than a dozen ganglia in Yusheng Ryunosuke's body that are different from ordinary people. What Ning Xiangwen has to do now is not to figure out the principle of these magic circuits, but to understand their distribution locations thoroughly, and make an identical one according to the shape of the ganglion in Yusheng Ryu's body according to the gourd drawing.

At this stage, the only one who can achieve such a high-precision operation is Ning Xiangwen, who is the most proficient in alchemy and has the assistance of Skynet's auxiliary brain, Ning Xiangwen began to scan Yusheng Ryunosuke's body with mental power according to the body data on the scanner. An hour later, Ning Xiangwen sweated profusely and withdrew his mental power from Yusheng Ryunosuke's body, gasping heavily, Ning Xiangwen sat on the sofa and drank slowly with a glass of water, now he has basically understood the structure of Yusheng Ryunosuke's body magic circuit, of course, he only knows what it is, and he doesn't know why, it is impossible to make any improvements on the original basis, but this is enough. Now it's a matter of who to use the magic circuit. As long as your own ideas are feasible, then it is not a problem to have a stronger magic circuit in the future, now you just need to experiment with whether your own ideas are feasible.

The four members of the war squad, first of all, they ruled it out, and now it is too difficult to transform the magic circuit of their own body, and it is difficult for doctors to heal themselves, have you ever seen that doctor who can perform difficult surgical operations on himself? Once the Magic Circuit is in possession, anyone in the Squad can be chosen by the Holy Grail immediately. After all, the members of the war squad have a strong obsession with survival. However, there are also strong and weak in this, and among the other three, I am afraid that the most obsessive is Erin. D. Kent: Auntie!

Ning Xiangwen stood up and said, "Then, let's start, carry out the body transformation of the magic circuit, the first one is Erin. D. Kent: Auntie, let's get started! A few people cleaned up the room a little, making room for a small open space, and in the flashing arc, Ning Xiangwen launched alchemy to refine a comfortable high-legged single bed. Aunt D. Kent silently lay down on the single bed on high legs. Aunt D. Kent had some nervousness in her eyes. Ning Xiangwen took out his specially made virtual helmet, he needed the Skynet auxiliary brain to give him assistance and guidance in the transformation, Ning Xiangwen pressed Erin with both hands. D. Kent Auntie's body began to scan Erin with mental power. D. Kent Auntie's body structure, and then Ning Xiangwen's virtual helmet began to project Erin in Ning Xiangwen's eyes. D. Kent Auntie's body data and structure diagram at this moment, Skynet Auxiliary Brain quickly according to Erin. Aunt D. Kent's body data began to simulate 18 special ganglia on her body. Ning Xiangwen looked at Erin who was lying on the single bed. Aunt D. Kent, her body has overlapped with the virtual image in her eyes, and 18 points of light are shining.

Ning Xiangwen's heart was completely settled at this time. Rather enjoy the text press in Erin. D. Kent The hands on the body of the god began to emit subtle arcs, and the alchemy was activated, and then with the alchemy of Erin. Aunt D. Kent's body trembled slightly, and her face wrinkled and distorted slightly from the pain. Ning Xiangwen's forehead also began to sweat slightly, 3 minutes passed, the first point of light in Ning Xiangwen's eyes suddenly flashed, and then 3 minutes passed, the second point of light also suddenly lit up, and then the third point of light... Fourth, the time interval between the light lighting shortened with Ning Xiangwen's proficiency, when Ning Xiangwen lit up the eighteen light points in his eyes, only 40 minutes had passed, Ning Xiangwen wiped the sweat on his forehead, and looked at Erin who was lying on the single bed with his eyes closed. Aunt D. Kent said, "Erin. D. Kent Auntie, it's all right! "Erin, drenched in sweat. Aunt D. Kent slowly opened her eyes, and there was a hint of pain in her eyes. However, the whole person's mental state seems to be good.

Erin. Aunt D. Kent sat up. Ning Xiangwen continued: "Then now try to open the magic circuit that runs on you, imagine that there is a switch in your head, and after turning it on, there is a stream of energy circulating back and forth between the eighteen ganglia in your body..... Slowly Irene. Aunt D. Kent closed her eyes, and the room began to fall silent as Ning Xiangwen's words began to imagine. Everyone looked intently at Erin sitting on the single bed. Aunt D. Kent, about 5 minutes later. Suddenly, Irene. Aunt D. Kent's body twitched, as if she was in great pain. Then Ning Xiangwen was pleasantly surprised to see that three red spells formed a red pattern and slowly appeared in Erin. D. Kent Aunt Aunt's right hand on the back of her hand.

Ning Xiangwen was pleasantly surprised. It's done! The magic circuit was copied successfully, Erin. Aunt D. Kent has been chosen by the Holy Grail!! Erin. D. Kent Aunt also opened her eyes, she just felt a tearing pain in her body because of the opening of the magic circuit, and then she felt a burning pain from the back of her right hand, and when she opened her eyes, she saw a strange red pattern on the back of her right hand, this is the spell that Ning Xiangwen said? Summoned by the Holy Grail, Master? Ning Xiangwen calmed down, but Chen Yu beside Ning Xiangwen was disappointed at first, and then said with excitement on his face, Then we have to let Erin. D. Kent: What Heroic Spirit does Aunt summon? Saber？ Archer