@Roxhan he's the reason Jae-shin was sent to the human world ... at the begining, Jae-shin tampered with the book of names and swapped the death-date of this old man with his son ... bad sh!t went down but the old man was the one trying to trick Jae-shin in the first place ... well, sh!tty situation overall for the innocents that paid for all this (meaning Nok and the son)