Laon Hiljo is a chachaoong forcibly employed by Ja-Gwi. He first appears when he and Laon Haje launch an unprovoked attack on Mu-Young. He had been blinded (presumably) at a young age, but despite not being able to see, he seems to get around without any aids. It is unknown if he uses a special ability to gain awareness of his surroundings.
Hil Jo stands at about 5'7" tall and has shaggy silver hair with gray eyes. His eyes, however, are fake as his real eyes were apparently removed at a young age. It is implied that Ja-Gwi is the one who took his eyes, leaving a large scar across Hiljo's upper face, across the bridge of his nose. Though his eyes are fake, Yu-Jin notes that they move just like normal eyes, to the point that it is very difficult to tell that Hiljo is blind, much less that his eyes were not real.
He is always seen wearing a black and purple form-fitted outfit that looks to be designed for fighting. He sometimes wears a long coat over this outfit.
Hiljo has a serious, cynical personality, likely due to the extreme hardships he endured from a very young age. Although he is forced to be obedient to Ja-Gwi and follow his orders at the risk of his own life, it is obvious that Hil Jo does not enjoy working for him and he even finds subtle ways to disobey or withhold information from him.
He is fiercely protective of Haje and Jena, viewing them much like his own children or younger siblings. He is particularly protective of Jena due to her inability to fight, and although he is strict, it is due to his wanting to protect her as much as possible.
Despite being forced to work for Ja-Gwi, Hiljo seems to maintain a sense of morality, and his main goal is to somehow free himself and his family so they can live a life of freedom together, somewhere away from Ja-Gwi.
Hiljo never demonstrated any specific abilities beyond the enhanced physical characteristics and ability to create weapons that all Chachaoong possess. He seemed to be an expert in physical combat and used a variety of weapons from massive swords and throwing knives, to small, explosive projectiles of an unknown material.
Despite being unable to see, Hil Jo had no problems sensing what was going on in his surroundings. He was, however, unable to see details like physical appearance, or that Jena was making faces at him wen he made her angry. But he was more than capable of fighting and locating targets during combat; it's unknown if he was using a special ability to help, or if he was merely using sounds and vibrations or some other natural means to move around unimpeded.
- Laon Haje - Hiljo maintains a father- or older brother-like relationship with Haje, having raised him from a young age. Because Haje also has fighting skills, Hil Jo seems to frequently rely on him for support and to help protect Jena. Regardless, he is extremely protective of Haje and cares for him like family, despite being unrelated. He has taken care of Haje longer than Jena and, as such, their relationship is much closer.
- Laon Jena - Hiljo maintains a father- or older brother-like relationship with Jena, having raised her and Haje from a young age. Hiljo is even more protective of Jena than Haje since she has no skills or ability to fight and is often frustrated when she tries to act on her own.
Not much is known about Hiljo's history before he took in Haje and Jena. Hiljo is the oldest surviving prisoner of Ja-Gwi as most of them were killed by their master at some point or another. Although Hiljo could not see how they were killed, their screams of pain would sometimes haunt him. Based on Yi-Mae's explanations, it can be assumed that Ja-Gwi found Hiljo at a very young age and intentionally destroyed his eyes before placing a mark on him that would allow Ja-Gwi to instantly kill him should Hiljo ever disobey.
At a later point in time, Haje was also found and handicapped by Ja-Gwi in a similar manner. Hiljo took him in and raised him, and later took in Jena as well, convincing Ja-Gwi that he had no need to maim her because as a girl, she would be too weak to fight. It is unknown what his exact age is or exactly how long he spent in Ja-Gwi's service but it is unlikely that he knew any life outside of being enslaved to Ja-Gwi.
(Major spoilers beyond this point)
He was murdered by Ja-Gwi after refusing to kill Yu-Jin.