Goo Hwi

Goo Hwi, the Heaven Ravager King (천잔왕天殘王 구휘, Cheonjan-wang Guhwi; "Heaven Ravager King, Goo Hwi") is a senior member of the old murim, being a part of the Sage Forest, and the leader of the legendary band of assassins, the Black Snake. In the past he was feared as one of the Twelve Supreme Masters, being one of the Four Heavenly Kings of the chaotic murim. He is also the older brother of Sohee, the father of the former Lady of the Baekma Valley, and the grandfather of Jin Garyeong, the current Lady. (Source: Wiki)