Kirei Kotomine, though not evil, was an antagonist.
He was born with a personality defect, unable to find beauty in what others called beautiful things.
Facing Irisviel, who was as beautiful as a flower and could no longer retaliate, his heart felt no ripple.
In his view, even if the Magus of the Einzbern Family were truly human, he would still feel no pity or emotion.
As an Executor of the Church, he had no concept of 'empathy for one's kind'.
Meeting on the battlefield, life and death were commonplace.
What's more, the other party was an enemy hindering his progress, so using her to buy time carried no psychological burden.
Therefore, facing the threat from behind, he unhesitatingly used Irisviel as a sandbag to gain himself some breathing room.
Watching Irisviel being thrown as a human shield by Kirei Kotomine, two options flashed through Chen Yu's mind.
Option one: Ignore her, and cleave both Kirei Kotomine and Irisviel in half.
Reward: Holy Grail War participant -1, Kiritsugu Emiya's anger +1.
Option two: Abandon the attack and catch Irisviel.
Reward: Irisviel's favorability +1. Nyarlathotep's jealousy +1.
Seeing Irisviel getting closer and closer, and with limited time, Chen Yu didn't overthink it and subconsciously chose a third option.
The moment Irisviel was about to collide with him, Chen Yu immediately manipulated his Iron Suit to dodge the incoming Irisviel, then once again, with his lightsaber in hand, he slashed towards Kirei Kotomine.
Although he avoided colliding with Irisviel in mid-air, Mrs. Irisviel, under the influence of gravity and inertia, traced a perfect parabola, flailing her limbs before crashing head-first into a tree trunk.
Her forehead made intimate contact with the trunk of a mature tree.
With a crisp 'bang', a good head indeed makes a good sound.
The purpose of Einzbern's homunculi was determined during the design phase; both body and mind were produced in optimal condition according to their objective.
However, the Einzbern Family only molded Irisviel's body to serve as a mobile 'holy grail vessel', not endowing her with a powerful physique, nor did they intend to make her a muscle-bound Barbie.
Therefore, Irisviel's physical fitness was not strong; she merely had twice the anti-magic ability of an ordinary person.
After her head violently collided with the tree, Irisviel fainted.
Hearing the crash from behind, Chen Yu ignored it, continuing to control his Iron Suit to move rapidly, accelerating towards Kirei Kotomine, his lightsaber leaving trails of green afterimages in the air, pressing directly towards Kirei Kotomine.
Sound like thunder, fast like lightning.
For Kirei Kotomine, Irisviel buying him even a moment was enough.
Facing Chen Yu's attack, Kirei Kotomine immediately dodged Chen Yu's slash, while simultaneously thrusting out his Black Keys, attempting to strike Chen Yu.
But the Iron Suit on Chen Yu was personally crafted by Tony, completely unafraid of ordinary thermal weapons, let alone Black Keys, which focused on spiritual interference rather than physical attack.
Even if Kirei Kotomine possessed the power to embed Black Keys into concrete walls with his bare hands, he couldn't penetrate the defense of Chen Yu's Iron Suit.
The concept of 'Curse of Restoration Nullification' attached to the Black Keys was even more useless against the Iron Suit's defense.
Facing an enemy whose defense he couldn't breach, Kirei Kotomine's expression darkened. Seeing the lightsaber attack again, Kirei Kotomine stomped the ground, his body instantly retreating, quickly moving out of the lightsaber's attack range.
He stared intently at Chen Yu, his eyes grave. As an Executor of the Church, countless experiences of bloody battles told Kirei Kotomine that the energy lightsaber in the opponent's hand was extremely dangerous, filled with a dense aura of death.
It was like a magical formalcraft or a Servant's noble phantasm; it might have special effects, and he absolutely couldn't be struck by that energy sword.
"Who are you?"
Chen Yu saw Kirei Kotomine quickly evade his attack, a little surprised.
As expected of a Master who elevated Bajiquan to 'Kirei-style Human Destruction Art', Kirei Kotomine's physical reaction ability was unparalleled.
Not only did he dodge his slash in an instant, but he also managed to counter with a Black Key.
If he hadn't been protected by his Iron Suit, he would have 'flipped over'.
Of course, it was precisely because he knew the opponent couldn't breach his defense that Chen Yu was so fearless.
After all, Chen Yu had some self-awareness; if it weren't for the equipment advantage, he wouldn't dare to engage Kirei Kotomine in close combat for two rounds.
Seeing Kirei Kotomine ask who he was, Chen Yu mimicked Nyarlathotep's Kamen Rider transformation pose.
"I'm just a passing-by Kamen Rider."
"Kamen Rider?"
A hint of confusion flashed in Kirei Kotomine's eyes. He had never heard of the name Kamen Rider, nor did he know the origin of the meme Chen Yu was referring to.
He didn't care who Chen Yu was; he only wanted to know if the opponent's purpose conflicted with his own goal.
Kirei Kotomine's mind remained tense. Facing an enemy protected by what seemed like an iron turtle shell, even he, a seasoned veteran, found it extremely troublesome.
Moreover, in the recent skirmish, his Black Keys couldn't penetrate the opponent's defense, and coupled with the energy weapon in the opponent's hand, if he were held up by such an enemy, he might not be able to reach Einzbern Castle.
To eliminate such an enemy, it would likely require the Servant Assassin to intervene.
But at this moment, Assassin was in a state of feigned 'death'. If Assassin's survival were revealed now, it would be a loss-making endeavor.
Under the effect of the Confundo, Kirei Kotomine didn't recognize Chen Yu's voice as similar to the young boy he had met at the Hongzhou Yan Sui Guan Ā· Taishan Chinese restaurant. However, Kirei Kotomine had already concluded that the opponent was also an enemy trying to prevent him from reaching Einzbern Castle and meeting Kiritsugu Emiya.
But even though he was mentally prepared for wasted effort, Kirei Kotomine still asked Chen Yu, "Are you also here to stop me from reaching Kiritsugu Emiya?"
Chen Yu pointed to Maiya, who was lying unconscious nearby, and then to Irisviel, who had just fainted behind him, indicating his intention.
"You can go wherever you want; I'm just here to rescue these two young women you defeated and rendered incapacitated."
Hearing Chen Yu's reply, Kirei Kotomine breathed a sigh of relief.
"Young women? You're here for the 'holy grail vessel' homunculus? In that case, I'll leave the homunculus with you for now."
The 'holy grail vessel' could collect the souls of the seven Servants summoned who were ultimately defeated and died, acting as the key to open the greater grail. Controlling the holy grail vessel would determine the final landing spot of the Holy Grail, gaining a head start.
Since the opponent coveted the holy grail vessel, they should be someone related to the Holy Grail War.
However, in the currently collected data, there was general information on the other Servants and Masters, but the data for Caster's Master was completely blank.
The opponent seemed to have sprung from a rock, with a completely blank identity; no relevant information had been found.
By process of elimination, Kirei Kotomine naturally suspected that You-Know-Who before him was, in all likelihood, Caster's Master.
The opponent's purpose in seizing the 'holy grail vessel' was also to control the initiative of the Holy Grail War.
If Tokiomi were here, he would certainly contend with the opponent for ownership of the 'holy grail vessel'. But at this moment, his target was not the homunculus serving as the 'holy grail vessel', but Kiritsugu Emiya, who was still fiercely fighting in Einzbern Castle!
Since their goals didn't conflict at this time, there was no need for a fight to the death now.
It was best not to fight; he had already been delayed by these two women for some time. If the delay became too long and Kiritsugu Emiya was killed by Kenneth, his participation in the Holy Grail War would be meaningless.
Kirei Kotomine still believed that Kiritsugu Emiya was not Kenneth's match, and that Saber's skill was not Lancer's match.
After confirming that the opponent was not an enemy trying to prevent him from going to Einzbern Castle, Kirei Kotomine remained tense, rapidly retreating directly away from Chen Yu.
Even though their objectives were different, Kirei Kotomine still dared not turn his back on the opponent.
After creating a certain distance, until both their figures were obscured by trees and no longer visible, Kirei Kotomine then abruptly rushed towards Einzbern Castle.
After seeing Kirei Kotomine disappear from sight, Chen Yu finally walked over to Maiya, first healing her injuries, then casting a Confundo on both Maiya and Irisviel, and then carrying the two unconscious women, he flew towards the Matou Residence.