Um Ain is the main villian though but she didn't even know about him drinking poison to build up immunity. She literally doesn't think about anything but basically hang out with Ain and treat him well. And I disagree with your second point since it was a novel so it wouldn't be strange to cover details about the villian as some sort of plot ploy. My point is though is exactly that - this story doesn't cover what is talked about/isn't talked about.
I like both of your perspectives Mandy and soy of the bean usually main villains/villainess will have almost as much information and background as the heros/heroines because honesty there's no good character growth, conflict, or plot without opposition and I always wonder what circumstances happened because the statement "I will never..." is hard to hold up and maybe the path of darkness seems a whole lot better. I also think that if the story was focusing more on the power of good vanquishing evil then it doesn't matter about the person's past as long as the hero/heroine gets their time to shine. Maybe something like an illness for Duke Cassius was something very possible to come from the physical and mental strain he's gone through but it wasn't something that the author went into because the focus was more on Ain's abilities and his trauma at the hands of his stepmother. I like that the female protagonist's past is interesting since she was a teacher for like daycare/pre-k or kindergarten who always wanted a family of her own and an orphan...even wanting Ain to have a happier childhood is sweet but it frustrates me because Duke Cass had the same childhood and he's been acting interested in love, family, connection for quite some time now. Glad she just now realized it.( ̄∇ ̄")
Having a hard time discerning what your point is, but I agree that most isekei/reincarnation plots have a pretty OP main character bc they utilize their past knowledge which makes growth a bit lackluster; however, the MC is incredibly mediocre (in my opinion). Literally what has the plot been for the last 30 chapters besides her hanging out with Ain and then eventually with the Duke?? She has no personality besides "being a step mom," has had 0 growth, and the plot has yet to kick in. I know that it's slow moving but at this point it'll be chapter 200 before we even get to see conflict between Ain and the original story's hero. Either way, thanks for respecting my opinion and I guess this story just isn't for me.
Yea, you're right even though I'm a sucker for the cute moments this can't be compared to other reincarnated heroines who make the most of their time advancing their skills, maybe strengthen their home against invaders, or preparing for future encounters. It really seems that for the most part they exist in a bubble or something. ( ̄ε(# ̄)Σ
What I don't like about the story is that it doesn't clearly establish what she knows/doesn't know from reading the novel in her previous life. I feel like the Duke's illness should be mentioned somewhere in there but she's seems to be clueless on everything but Ain turning evil because of maltreatment. Other than that, eh.