Based on what I've read so far I truly believe that he is NOT in love with her. What he loves is control, he made yugyeong into his own kind of sick and twisted definition of trophy wife. IMO, he wanted yugyeong to be just like a doll and never really do anything against to what he wishes (i.e. making sure he gets his daughter). He is incredibly selfish and is basically a terrible fucked up spouse and father overall. In a sense, he's like a puppeteer--i mean, he literally manipulated his way into building a family and treats them like so. If you read more into it, it definitely feels as if he is incapable of love too.
I think he loves her but is manipulative as well, both can coexist.