@JWChibi they mentioned in earlier chapter that in hardmode (the villainess route), favorability may start at 0% and even in the negatives, it's hard to raise( as opposed to the MC route), and drops back to 0% quite easily, and reaching the negative with a character can signify a death ending.
Hmm, not gonna lie, she be kinda dumb sometimes. Of course the favourability is gonna drop when there’s an intruder and she doesn’t even explain anything.