Those who do not know Kiritsugu well simply believe that the title "Magus Killer" comes from assassinating too many magi with modern weapons, or perhaps openly bombing them to death with artillery. However, those who know of this man's existence more or less have to admit that the title of Magus Killer is, to some extent, truly fitting for the magus before them.
After all, as long as this man is given an opening, and as long as the targeted magus lacks physical defense against bullets, once injured by this man's bullet, they can forget about being a magus for the rest of their life. Moreover, not only will they cease to be a magus, but their body will also suffer severe sequelae due to the destruction of this virtual organ.
Ranging from a part of the body not obeying commands to full-body paralysis in severe cases, and this is assuming timely medical treatment. Do not forget, that is a bullet piercing directly through the body; sometimes the sheer destructive power of the bullet alone is enough to be fatal. If one wants to restore their original normal body, or at least recover to a state where the body can move freely...
Unless someone is precise or powerful enough to cut the simulated organs—the Magic Circuits—one by one and reconnect them, and reconnect them correctly at that.
At least for now, no one in the magus world has heard of anyone capable of performing such a surgery. Someone who could perform such a surgery would definitely be treated as an honored guest by various powerful factions and families.
The difficulty of this surgery is no less than Aslan creating an Artificial God. Unless one is an extremely gifted genius, let alone completing this surgery, even conducting in-depth research would be unlikely. Perhaps only one such person appears every few centuries, and this gifted person would also have to spend their time on this specific research.
So simply put, don't think about it; just obediently accept your fate, lie down, and wait for death.
Do not forget that the world of magi is itself a dog-eat-dog world. If it became known that a magus had turned into such a state, that magus would likely be devoured clean by others. This applies whether it is the magus's friends or enemies. After all, for most magi, benefits are far more important than friendship.
The Magus Killer looked at the monster angrily destroying the defensive barrier with its fists, threw the cigarette in his hand directly onto the ground, and stomped it out. Then, he silently pulled back a certain distance. Sigma noticed the silent retreating action of Kiritsugu, who could be considered his uncle, so he actively took the weapon in his hand and stood at the very front, attracting the attention of this guy before them.
After all, Sigma's body had undergone experimental modification. In terms of physical fitness among all the magi present, perhaps no one could be stronger than him. In another world line, this boy had the aptitude to challenge the impossible and succeed. To some extent, he fits the protagonist persona perfectly.
Originally, this magus who didn't want to be human was already very unhappy that his attacks were blocked time and again. Now that a brat wanted to clash with him head-on, how could he not be angry? He was practically bristling with rage. This was the effect Sigma wanted. Even if this guy would sober up after a while, this short moment should be enough for Kiritsugu to play his trump card.
And this odd-looking existence was constantly pounding the magical barrier with his fists. "Damn it! If you have the skill, don't keep shrinking inside that turtle shell!! Come out and face me head-on!! Let's have a fist-to-flesh collision, a clash between magecraft and magecraft, let blood spill over the earth, and let our voices resound throughout the entire world!!"
Punch after punch smashed onto the barrier, causing wave after wave of ripples to pass over the entire barrier. If not for a portion of Sigma's attacks attracting this magus—let's tentatively call him a magus—attracting this magus's gaze, the entire barrier would probably have broken, opening a small gap.
At that time, trying to destroy it would not be too difficult a task. After all, the opening would already be made; the first step is always the hardest, and what follows will not be harder than the beginning.
Marisbury was also constantly using magecraft to attract the attention of the guy before him. He even employed some Grand Magecraft. The starlight in the sky flickered constantly, followed by magical energy falling from the heavens. Such an attack was enough to inflict heavy damage on the guy before him, provided this guy did not defend or regenerate his body.
However, this was just wishful thinking. Watching the attack falling from the sky, this existence raised one of his hands and began to wrap his body in magical energy. At the same time, a powerful life force constantly wound around his arm. Various spells combined, making the magical energy appearing in front of this arm and palm look like a powerful shield.
Rin raised her right hand, and a large number of gems began to rotate around it. Shinji also loaded all the magical energy crystals into his weapon. The firearms in Sigma's hands began to aim at the guy's other arm. To make Kiritsugu's surprise attack fatal in one blow, they had to make the guy before them ignore the defense of his weak point as much as possible, while also restricting his movement.
The gems in Rin's hand flew into the sky as she raised her hand, then transformed into ice-blue power scattering in all directions. Weapon after weapon, resembling both ice and gems, appeared in mid-air, all aimed at the guy before them. Then, as her finger fell, these swords stabbed into the ground, forming a force similar to imprisonment.
Shinji and Sigma also blasted out all their magical energy with their modified firearms, forcing this existence to raise his other arm to block. As for those gems confining him in place, this existence merely curled his lips, not taking them to heart. As long as he blocked this round of attacks, with a wave of his arms, one of the spells within his body would surely be able to destroy this binding force before him.
"Time Alter—Octuple Accel!!"
A figure passed through the defense quickly like a black shadow, arriving behind this existence. This existence, no longer human in shape, turned his head quickly, but his eyes locked onto only a pitch-black gun muzzle. A stream of magical energy began to form a defense, but the owner of this firearm was a fraction faster.
Accompanying the pulling of the trigger, an Origin Bullet was shot directly into this guy's back.
The wound, which he originally thought could be recovered by using the magecraft within his body, did not go as this magus wished at this moment. Not only that, it was like an artwork pieced together to look seamless being smashed onto the ground; in the next moment, the magecraft within this existence exploded directly.