Well as far as I know (which is from the comments here) the fl kills him and then he wakes up as a zombie 1000 years later and fl also wakes up as an immortal being for more knowledge scroll down to the more enlightened people who have read the novel
I think he don't want to accept his feelings. Same as fl, she will never to accept him. This'll turn into some psychological shit.
I wish The manhwa's ending is different from the novel.. ╥﹏╥