One of the things i love about this manga is how the mc rightly calls out the emperor on all the harm he's done and is still doing to his kids. And yes, that does include the replacement daughter as well; her personality, while less than ideal, is a direct result of the emperor's doting, and for him to cast her aside just because the mc shows up is just adding further injury to harm. I'd like to see the two sisters reconcile their differences and bond as they grow up, but the author has already broken from the norm so far, so we'll see where this goes
