Khaki is leebin and Hwagok’s kid Lee Hwa I’m not sure why he calls him that though. Michael I believe was Lee bin’s old name or His father’s name. Razel is like Hwa Gok a Lycanthrope turned Vampire and an ex lover of the father. That was previously mentioned. “His first and Last lover.”
Now if you are still confused. All the people Michael (the dad) has turned into a vampire are referred to as siblings or brothers and sisters. and Razel is now a new character (Antagonist) and brother that has been introduced. There is still so much to unpack in the next chapter and things have become more interesting. I hope this cleared things up for you and if you have more questions I feel free to ask :)
Khaki who????