Sakura and Shirou
The two of them pondered her question for a moment, before Shirou spoke up.
"Well, back home we dealt with whoever was necessary, so we could protect and save people", he said. "Here, though, the strongest supernaturals are simply too strong for us, so we've been bounty-hunting, and helping where we could", he said, clearly a little embarrassed and downbeat about his inability to deal with the most powerful enemies.
"Now that we have Rider, though, we can take on stronger targets. And Senpai's magic means that he can ambush people who are a lot stronger than we are in a straight fight", Sakura added, her admiration of Shirou clear.
"But, still, you're right, we need to be cautious. I'm not sure even Rider could defeat this woman", she finished. "We need to plan and see if we can find a weakness. And try to stop her killing anyone else, if we can."