The fact that he had a child suddenly explains why the Monarch of Fangs of all people was the only Monarch that sought mercy from Sung Jin Woo (before becoming enraged when the proposal for receiving mercy was both an insult and a death sentence.) It was such an interesting moment since it seemed to run counter to his philosophies, the only explanation then being that the Monarch of Fangs, as a beast, did so because he instinctually new he had no shot, but it makes more sense that he'd be willing to give up his pride in surrender if he was concerned about his descendant's survival (though obviously he couldn't trust the "traitorous" Shadow Monarch either.)