Rider
Rider listened to Vanguard's speech, somewhat confused as to what he was talking about. Nevertheless, she could not disagree with the sentiment he was expressing. Hurting Sakura in this manner was a crime worthy of the most painful death imaginable.
Before Rider could say anything, though, Rin spoke up, acknowedging Vanguard's statement before launching into her own explanation of why they needed to kill the thing that had hurt Sakura so badly. Rider nodded in agreement with Rin's words.
"I agree. A monster who would hurt Sakura like this deserves nothing more than a painful death, and I will happily assist you in finding and destroying them.
Rin, you are right, someone must surely have seen a fight of that scale and, in this world, there is no-one around to erase the evidence. If we go looking now, we will surely find some clues", she said.
Before they could leave, however, Rider recalled the other Shirou, still presumably stood around waiting for them to return. She couldn't allow him to come to harm. That would hurt her former master far more than Faust's death had hurt her current one, and that was something she could never allow.
"We need to do something with the other Shirou, though. He can't stay here, not with Sakura as upset as she is right now, but it's not safe to just throw him out on the streets at this time of night."