that makes so much senseShe's trying to build up to the public reveal eventually.
Because if she goes out to the public and show off her power, they'd think she use some tricks to make it happen.
Whereas by spreading the achievement of the 'mysterious swordsmaster' until this person is an established fact then she can come prove it's her all along (at least her Fame stat will definitely rise from those not in denial)
In this case it's just a mix of her snapping from captain's condescending attitude + earlier anger of trash dad trying to steal her achievement (by saying Ante did it) and because she's trying to put the knights in their place NOW so she can start grabbing some with potentials for her own knight order (well, for when the real Renee return)
I mean, she didn't just make them faint. Those butterflies were cutting them up. The "fainting" in this case was probably due to blood loss. The ability she used is pretty common in Wuxia/Murim stories. Where sword skills have reached such a level as to transcend into what's basically magic.That's disappointing. After the last chapter, I was eagerly waiting for the FL to humiliate those knights by dominating them at what they're most proud of, swordfighting. Crushing them like they're housecats facing a tiger. Not "poof, magic butterflies make everybody faint!" Sure, it's an imppressive display of power, but it's not cathartic, especially with the mood change as the MLs step in.