Rider stood there horrified as Kiyoshi attacked, fully expecting his opponent to show him no mercy. Knowing she would have to intervene to protect him before he got himself killed, Rider tensed herself and prepared to attack the asshole, even if that meant losing her advantage. However, to her extreme surprise, their opponent instead chose to sheathe his sword, using the scabbard to block Kiyoshi's attacks.
Eh, what? Rider thought.
She simply could not understand him. He seemed to revel in fighting and killing and, yet, he had refused to even use his weapon for defence against Kiyoshi.
Oh, I see, Kiyoshi is not a "worthy" opponent, so he won't fight him, she thought.
Kiyoshi was equally surprised by the man's actions. Despite the killing intent radiating off him, he had shown no indication of fighting back, instead using his scabbard to block Kiyoshi's attacks. Despite this, Kiyoshi continued to swing his swords at the man, noticing with pride that he had managed to cause some damage, albeit superficial.
See, dad, I can beat the bad guys like a real hero, he thought, proudly.
Then, his opponent spoke up.
"Oh you're pretty good, son. And you got spirit too. I like that", he said.
Kiyoshi smiled at the compliment, although he was somewhat unnerved about the fact that the bad guy seemed to like him. After all, bad guys liked evil things, right? Meanwhile, Rider cringed.
Don't encourage him you asshole! she thought.
With his comment, the man jumped towards Rider. As he did so, Rider tensed herself, expecting an attack. But, to her surprise, he ignored her entirely, focussing instead on Kiyoshi.
"What's you name kiddo?", he said.
"That's none of your damn business, as... moron", Rider shouted, mincing her words slightly in the presence of the two children. "Now, leave us alone!"
Meanwhile, Kiyoshi reacted to Shuya's move by charging in his direction at full speed. Ignoring his Aunt's rebuttal, he responded to Shuya's question.
"My name is Emiya Kiyoshi, and I want to be a hero like my father. Now, leave my Aunt alone before I make you!" he said, angrily.
Rider had to restrain herself from facepalming. She knew Kiyoshi's intentions were good, but it was clear from his actions that their opponent was not overly interested in continuing the conflict further, perhaps because he now knew that she lacked the prana necessary to make it a good fight. And, she couldn't help but notice that he had been protecting the girl over his shoulder, too.
Wait, she looks familiar, Rider thought.
But, before she could think any further on the topic, she noticed that Taiga had opened her eyes. Then, suddenly, she felt a strong flow of mana around the girl, and saw her eyes begin to glow.
What the hell? she thought.
Then, the girl spoke up.
"stop fighting right now!", she said.
Suddenly, Kiyoshi felt his body get heavy, slowing him to a stop. He felt nauseous and lightheaded, and it seemed like his mind and body were no longer fully connected. His body was acting of its own accord, doing whatever was necessary to obey the girl's command that they not fight.
No, I have to protect Aunty Rider! he thought.
But, his body was simply not complying with his demands. He was able to summon up enough willpower to begin moving once more, albeit more slowly but, as he approached the man, the mana supply to his swords was abrupty cut off, his body reacting to ensure the girl's command would be obeyed. No amount of willing on Kiyoshi's part could make them return. Eventually, he gave up, stopping a metre of so short of the man and staring at him angrily.
Meanwhile, Rider watched Kiyoshi's struggle with confusion, at least initially. However, as she looked on, the pieces began to slot together in her mind. A flow of mana into the girl, followed by glowing eyes and, finally, a command which Kiyoshi and, seemingly, also his opponent had been affected by. But, yet, she had not felt anything.
Mystic eyes of persuasion. And, pretty powerful ones, seemingly.
That explained why Kiyoshi had been stopped in his tracks and, also, why she was unaffected.
My blindfold protects me, she thought.
Then, it dawned on her.
This is a perfect opportunity. The asshole can't fight. I can just stick a nail in his back.
But, yet, she hesitated. Whilst killing him in cold blood was not something she had any real issue with, she knew that it was unlikely Taiga would see it the same way, and even Kiyoshi would probably not be too happy about it. Further, if she did kill the man, Taiga would almost certainly feel responsible for putting him in that position, which was not something she wanted to inflict on the girl. Plus, Taiga didn't seem aware that she was unaffected, and it was probably in her interests for that to continue to be the case. So, she decided to play along, changing back into her normal clothes and dismissing her weapons.
Now that the battle was over, though, she had questions to ask of the man. Specifically, why the hell he was carrying an unconscious girl over his shoulder who he seemingly wanted to protect, and why he had attacked her whilst he was.
"OK, idiot, can you please explain why you're carrying an unconscious girl over your shoulder, and why the hell you thought it was a good idea to attack me whilst doing so?"
Then, Rider looked more closely.
Isa? she thought, remembering the sweet young girl from earlier. And, she looked hurt, too.
Rider remembered how kind and sweet the girl had been, and felt angry to see her like this. She knew she couldn't trust this asshole to look after the girl, particularly since he was likely responsible for the situation she was in in the first place.
"What did you do to Isa?", she said, angrily.