my theory is that geumsun loved the human 704 and 704 betrayed him or they had a fight before 704 killed himself and become a reaper. either way geumsun is now resentful of the reaper 704 hence their bad relationship but is also paranoid of losing him again hence the overprotectiveness when it comes to 704 meeting hwan. also since hwan's powers have something to do with memories he must be able to bring back 704's memories but it will probably mess 704 up which is why geumsun never told 704 about his past life.
my theory is that geumsun loved the human 704 and 704 betrayed him or they had a fight before 704 killed himself and become a reaper. either way geumsun is now resentful of the reaper 704 hence their bad relationship but is also paranoid of losing him again hence the overprotectiveness when it comes to 704 meeting hwan.
also since hwan's powers have something to do with memories he must be able to bring back 704's memories but it will probably mess 704 up which is why geumsun never told 704 about his past life.