Chuh-Yong is a mysterious chachaoong who directly serves under, and listens only to, Jack O' Lantern. He is one of the more active chachaoongs with a great many responsibilities, including ensuring that the transition from the first to the second generation is as smooth as possible and regulating the first generation. He seems to be aware of nearly everything that is going on and frequently follows or watches other characters to either ensure their fights do not get out of hand, or for other reasons.
Most of the other characters are incredibly intimidated by him, and it is implied that he is one of the most powerful chachaoongs apart from Jack.
At 6'2", Chuh-Yong is one of the tallest, most physically imposing characters. Like many of the older chachaoongs, he usually dresses in traditional robes and clothing though his are significantly more ornate than what most others wear. He has swirled markings over most of his body, but keeps them covered by his extravagant black and white clothes—which cover everything apart from his hands and head. Chuh Yong is always seen with a traditional hat adorned with flowers and vines.
Both his hair and eyes are coral-pink, and like many of the male chachaoongs, he keeps his hair extremely long. When angry, or using his abilities, the whites of his eyes turn black. His fingernails are black, but were naturally colored when he was younger, as seen in flashback sequences.
Chuh Yong usually presents the face of a stoic, almost emotionless observer but in several encounters he has been shown to have a very quick, often violent temper and sadistic tendencies. He took a great deal of pleasure from the idea of finally being able to punish Ja Gwi, and was highly amused by the fact that Ja Gwi assumed Chuh-Yong would kill him rather than torment him for his crimes.
He is thought by many people (particularly by Mu-Young) to be either a pervert, or gay though the latter is untrue. Chuh-Yong does not, however, deny being a pervert and seems to enjoy such accusations.
Chuh-Yong has a surprisingly soft side, as Yi-Mae noted that he would take special care of Hil Jo due to the hardships he endured from a very young age. Nevertheless, Chuh-Yong is completely loyal to Jack and will follow his orders without fail, even if he does not understand or agree with them. He is merciless when dealing with criminals and people who have broken Jack's laws.
Chuh-Yong's abilities are as mysterious as he is. He can manipulate souls and ghosts, using them to possess people and make them act as he wishes. He uses this ability to clear Humans from areas where chachaoongs are engaged in conflicts and also used this ability to manipulate Mu-Young and Ignatio so they would meet up in an abandoned park. When he apprehended Ja Gwi, there were also many souls of the deceased present, as well as a large, demonic form. It's unclear whether he was manipulating those souls or if they were there of their own volition to torment Ja Gwi.
He has also been seen teleporting from one location to another over long distances, and taking others with him on some occasions.
The marks on his body are related to his powers as, when he found the body of an infant chachaoong, the marks took on a smoke-like appearance and appeared to disintegrate the body of the child. Since one of his responsibilities is taking care of the dead, it appears he also disposes of the bodies and possibly absorbs their spirits by using the marks on his body.
Jack O' Lantern - Chuh-Yong has served Jack for many years. Despite this, even Chuh-Yong is unaware of all Jack's plans and everything he's thinking. Regardless, he remains unequivocably loyal and will listen only to Jack and no one else.
Ignatio - Chuh-Yong found Ignatio and Mu Young as infants and personally raised them as he attempted to work out if they were identical twins or not. Because Chuh-Yong seperated Ignatio from his brother. Though they had a bad relationship for a long time, it's possibly on the mend now that he no longer has to kill one of the brothers.
Mu-Young - Mu-Young is extremely intimidated by Chuh-Yong and considers him an unrepetant pervert, which Chuh-Yong seems to find rather amusing. Chuh-Yong spends a great deal of his time stalking and watching Mu-Young due to the uniqueness of his situation.
Yi-Mae - Their exact history is unknown but Yi-Mae and Chuh-Yong do not seem to be on good terms at all. Yi-Mae is clearly afraid of him and Chuh-Yong does not like him and accused him of trying to deceive him and Jack.
Be-Gak - Their exact relationship is unknown but it was said that Be-Gak and Chuh-Yong had a fight at one point with the implication being that Be-Gak lost and was injured.
Yu-Jin - Chuh-Yong specifically dislikes Yu-Jin due to the latter's refusing to accept his responsibility, and because he is running away from his inheritance. Because Yu-Jin will not accept the throne, Chuh-Yong does not feel obligated to show him any particular respect or deference and has shown that he will not hesitate to fight him if need be.
- Though apparently not one of the nine Tals, Chuh-Yong appears to be based on another historic mask from a Korean mask drama. In the Cho Yong-tal dance, the character is the son of a dragon god who becomes a close servant and confidant of a king. Chuh-Yong's character design strongly resembles this mask as well as his position as a king's subordinate being similar to the tale.
- Some fans speculate that Chuh-Yong's entity Gwishin is actually the soul of a chachaoong he killed at some point in the past.
Aside from the fact that he has worked for Jack for many years, not much is known about Chuh-Yong's distant past. He is, however, one of few chachaoongs able to withstand being in Jack's presence without fainting from the pressure of the king's massive power; in fact, he seems completely unaffected by it.
He has a great many duties among the chachaoongs. He cares for the dead and watches over their souls, and also seems to be the one responsible for meting out punishment to those who break Jack's rules. It is also his job to keep humans from finding out about chachaoongs. As such, he frequently spies on others so he can intervene in their fights, or remove Humans from the vicinity if need be. And finally, it's his responsibility to ensure a smooth transition from the first generation to the next. As such, he must get rid of all irregularities and aberrations such as Mu-Young and Ignatio as part of his job to regulate the first generation.
Chuh-Yong found Mu-Young and Ignatio when they were still infants. He noticed their identical appearance right away but was unsure if one might have a shape altering ability that could account for the similarity, so let them them live. He ended up raising the two himself, and found about their their identical powers when they both saw the strange markings on his body from extremely far away. Even then, he wasn't sure if one might have the ability to mimic the powers of another and decided it was too early to kill one of them as of yet.
When Chuh-Yong noticed, by chance, that the two had identical yongmas, he then separated the two, taking Mu-Young to the human world and leaving Ignatio alone on the mountain. He then told them they had to make a choice as to who would live and who would die. Later, after realizing that Ignatio and Mu Young would not fight, Chuh-Yong chose to kill Ignatio but couldn't bring himself to do it and hesitated long enough for Yu-Jin, Yi-Mae and, later, Jack himself, to intervene. Jack later told him not to burden himself with dealing with the situation as he had personally raised them and clearly has an emotional attachment to the brothers.