Bigak serves as one of the main antagonists in Part 1, and he is one that many characters, including Imae, fear. There quite a few chachaoongs who have sided with him because of this, whether they truly support him or not. His exact motives are unknown, but he has a particular interest in Imae and Yu Jin. He also seems to be the one who knows the most what is going on with Jack and the rise of the second generation of chachaoongs.
Bigak has yellow eyes like Yu Jin, long black hair that fades to red at the ends. He wears a large, blade-like earring on his left ear. He often wears a coat with a fur-lined collar when lurking about his base, but prefers black leather when out in public. He is frequently depicted with an unpleasant smirk, or a grin that borders on the insane.
Fans have noted similarities between his appearance and Yu Jin's awakened form.
Bigak is well-known among the chachaoongs for his strength and cruelty. While his presence tends to intimidate those around him, he seems somewhat lax in regards to his supporters and most of them seem to have a fair amount of freedom to move about as they wish. He usually has a calm exterior but he has described himself as lacking patience and self control; others refer to him as being unstable. He can be incredibly sly and cautious, and does not act rashly but is cruel to his followers, showing little patience for those who cross him or are no longer useful.
Regardless of his motives, he does not pick fights he knows he cannot win (or would be troublesome) such as with Jack or Cheoyong.
Like all chachaoongs, Bigak has the ability to materialize weapons from air. He wields a whip-like weapon which he uses to both restrain and attack enemies. He is said to be as strong as, possibly stronger, than some of the Tals, so it is unlikely that he has been revealed fighting at his full potential yet.
Like several other chachaoongs, Bigak also has the ability to "seal off" areas to prevent humans from entering them.
Bigak has a yongma named Ryuguheul, who has strips of prehensile cloth clipped to his clothing. This cloth can be manipulated to able to act as swords, impaling people even from a distance, as to defend against multiple attacks at once. The cloth is even capable of gripping and manipulating objects to at least some degree. Like Shadow and Shade, he does not speak.
- Imae: The two have an unresolved conflict that goes back a few years. The nature of their conflict, and what exactly is going on between the two lies in not just the mystery of Imae's past, but Yu Jin's awakened form as well. They do appear to hate one another a great deal.
- Jack O'Lantern: Jack makes no attempt to eliminate Bigak, in spite of the fact that he has killed many chachaoongs and has had a negative effect on the second king.
Part 1 Season 1Edit
Bigak is first mentioned in the story (but not by name) when Cheoyong asks Jack why he keeps around a guy who has killed many chachaoongs, and blames this person for the current behavior of the second king. Not long after, Maru tells Muyeong about the rumor among the chachaoongs that Imae disappeared two years ago because Bigak killed him.
Mano, observing the group of chachaoongs plotting to distract Imae and dispose of the next king, tells them to convey a message from Bigak to Imae: "I'm glad you're alive." Later during the group's confrontation with Imae, when one of the chachaoongs mention Bigak's name, it seems to alarm Imae, who then demands that they tell him where he is.
There is still tension between Bigak and Imae as they apparently had some sort of confrontation in the past. When Bigak meets Yu Jin for the first time, Bigak feels as if they had met somewhere before even though it was technically their first time meeting. Jin's flashback reveals that the potential nature of this meeting was far from being on good terms and the unawakened Jin exhibits a great deal of apprehension during their meeting, though he is not sure why.
Bigak has had unpleasant encounters with Cheoyong in the past, possibly due to causing a number of unnecessary deaths. His reputation among most chachaoongs is not good and he is generally viewed as being unstable. Those who do not support him try to avoid any involvement with him.