Not sure what is to love about the ML when the ML is kinda an asshole, at least I that regard, other than that, the premise is interesting and it is a good overall manhwa
if I were him, I'd still kill the king even if he sacrifices his daughter. Part because he's clearly scum and him being such scum is why his daughter became scum. And his sons are prolly scum too. So they'd gotta go.