Another weird plotline I don't really care for is Vivianne's. Not the character herself, she's fine, her recruitment quest and its results.
The main standout feature of the protag is we're 'malleable' and react well to transformatives, the main hangup of the villain is she's a demon and can't stop being a demon and for some reason can only have imp kids (even though we can specifically romance her daughter, who is not an imp).
Then Vivianne's quest is like
"ey so I casually messed with that milk you gave may, now I have on demand malleablility that's above your own and also I can become a demon or human at will, its super easy bro, dunno why no one else did this"