the prince was imposing his mother complex over Shuli. Turns out the prince has a lonely insecure childhood; his mother the 1st empress died in childbirth and his dad the emperor resents him over causing his beloved wife's death. He had no real parent figure that really cared for him. Then he meets Shuli and is smitten by her maternal, kindly nature and her strong resemblance to his own mother. But then he gets jealous over the stepchildren getting all her attention. So he schemes to bring about the moral downfall of the children so he can slip in as the model child and replace them as Shuli's new "son". It's all very psychological. Plus he also puts on a "good guy" facade to get people's attention and love. Apparently Jeremy falls in love with Shuli too, but it's unrequited.
I don't think I understand what the brother meant...I know it's supposed to be something, but my mind is like was it sexual abuse because I'm not getting it? Maybe i'm thinking too much, but I just don't understand the context.
@bribrie_6 You forgot about that douchebag of sword instructor which portrayed badly from old chapters. And yeah, most of the men in this manhwa is a fine guys.