"The woman that completely thrashed me right after saying that to obtain her I had to be stronger than her is hanging out with my brother, and they seem quite close, too... Hmm, he must be a weakling, lets duel him !'
Yeah we can see her diplomacy skills in action in the last few chapters, with how she's slaughtering an entire clan just for a dumbass horse with horns and all
What do you mean "There's a possibility she might also be a reincarnator ?" Wasn't she the girl screaming about being the main character or something ?