Claire was feeling that there was something very strange with that boy. Again, it wasn't just a matter of being arrogant or way too confident. He was giving the vibe that the knew his place, only that.
'I saw a lot of warriors before, of all sorts. I know how to recognize an arrogant idiot when I see one. Those are the ones that I needed to deal with the most. This boy isn't arrogant. He isn't measuring his strength based on his ego... The issue here is that I am not sure about it. The risk of going at full force against him is high because I can end up killing him...'
Claire didn't care about that boy being alive or not. She killed even close friends in exchange for huge quantities of money, so she would easily do it with someone she didn't know. However, there was something that boy had that touched her somehow. She was interested in him.