Responses

Not the Lu family but Lu Mingfeng, actually. It doesn't show much in the manhua but in the novel it IS mentioned that the parents always tried to discipline and punish him when he did something wrong but the older brother would either go against it or indulge him even more due to his guilt towards his bio brother.
Ik this may sound crazy but the adoptive brother is 100% a monster made by the Lu family. He ended up like that because of how they raised and treated him. They have absolutely no right to abandon him. The adoption meant they agreed to take care of him. Idc how shit he is their behaviour makes me sick.