Ko Suljun is a member of the Bamboo Guard who was helping Dochun out at the coast near the village. He is initially rude to the Hongmoon student that Dochun saved, but once he realizes what the student was capable of, he changes his mind completely. He later asks the student to investigate the whereabouts of Dochun's son Dodan, who seems to disappear every time the Blackram Marauders invade the village. He also tells the student to watch out for fellow Bamboo Guard Chengun as well.