He basically went crazy, he went mad crazy like he literally killed everyone and went to the emperor to kill him. He thought it was useless if his daughter isn't by his side anymore. No reason for him to continue living this hell, so he cut the head of the emperor, then killed himself while wishing to turn back time(?) Or was it Return her daughter(?) Idk kinda forgot.
So he wished for his daughter's happiness. Btw the FL(Jubeline) has 3 Lifetimes. The first was when she committed suicide, The second life is when she was a working women in korea, and the third life is this one. They basically had soooo much misunderstanding, it hurts reading the first life.