Rather than literally "the intent to murder someone" I meant it in the more "anime" sense of presence. A lot of times fighting ability/aura/etc is translated as killing intent not because the person actually intends to kill anyone, but because of their [i]capability[/i] to kill someone. A fighter who puts "killing intent" into their attack is just being serious, rather than having the mindset of a spar.

Rather than trying to expose her secret identity, Dai Xin's legitimately just complimenting her. He can tell from the subtleties of her movements, her breathing, and other things that she knows how to handle herself in a fight--whether or not she's a famous assassin, he has no idea, he just knows that this woman has the habits of a swordsmaster. Martial artists (in real life too, oddly enough) often have a lot of little things they do that are indicators to other fighters that "this person knows how to fight." Like, for me (not saying I'm a master or anything) I started noticing after several years that I don't walk around corners the same way as other people, I do what's called Tai Sabaki (body control) to shift myself from one direction to another without picking up my feet so that I can see in that new direction as quickly as possible.

If it's still a problem I can change it, though.