In the small island of Marado in the southernmost point of South Korea was the family of Ahn Areum. Her family’s industry focused on Marado Island’s tourism. As such, they ran an inn to accommodate the tourists visiting the island, with her as the owner despite her young age.
While on the way to Jeju Island, which was two kilometers away from Marado, an uncalled yet vicious thunderstorm caused the small boat she rode on to capsize. That was when Areum met Palaemon, known for saving sailors in distress. The god brought her to Jeju and back at Marado himself, and the rest was history. The relationship lasted for more than a year; at that point, Areum was discovered to be pregnant. The Ahn Family actually assumed that Palaemon, under the name Min-Ho, would be Areum’s future husband. Even so, he left them as soon as Areum gave birth to their firstborn son, Cheol-Su.
Unfortunately, Cheol-Su was born prematurely. What’s worse was that he had a severe congenital heart defect; it seemed that his heart had an abnormally large hole. The doctors residing in Marado told Areum that Cheol-Su needed a better medical attention at Jeju Island because he was already dying. While on the way to Jeju, his condition worsened, and his mother thought he was dead. Nevertheless, she hadn’t lost hope and still brought him to the hospital, where he was put under surgery. The operation cost a fortune, but Areum didn’t mind, because Cheol-Su lived in the end.
While Cheol-Su managed to survive death, he had to take medication outside the hospital for an indefinite amount of time. The hole in his heart was definitely sealed, but his overall condition was still unstable and very sensitive. If he spent too much playing, he started running out of breath and his chest hurt. As such, he was confined to his own house, inhaled oxygen often, and was pretty much spoiled because of the circumstances. If he ever went outside, he only walked during the cool mornings. Even the rise of temperature affected him.
Cheol-Su’s childhood was indeed lonely, with very few kids who actually understood him aside from his family. The rest of the children in their small village on Marado Island only made fun of him. For him, he really felt jealous and insecure. Whenever he felt his life was really miserable, he would run away from home to hide in a cave or walk along the shore by the sea. While it was understandable that his behavior was patterned after most children of Palaemon, the sea reminded him of his dream to go beyond Marado Island. Simply put, he wanted to be free.
While hanging around in the cave alone on the dawn of his thirteenth birthday, two scythian dracanae appeared from behind towering boulders. Out of fear and panic, he electrocuted the first dracanae with electroreceptive energies, which immediately turned to dust. The second one quickly made its way to constrict him with its trunk, but he started to grow shark teeth and ripped the monster apart. Dumbfounded and easily worn out, he fell unconscious for the following hour.
At the same time, South Korean pirates docked their yachts on Marado. Cheol-Su was unaware, or rather too late of the events that followed after. First posed as tourists, the pirates raided the village, pillaging it of anything they could find. Everything happened in a matter of an hour and as said, Cheol-Su was too late when he came home after waking up. His family was already dead, including his mother Areum. The strong odor of the blood all over made him snap. While on a vicious outrage, he killed his family's killers—two pirates at that—but also caused his house to blow up in a burst of flames.
Cheol-Su, assuming that he would die at any given time, made his way to the seashore where he wanted to be buried. However, his father, Palaemon, pitied how his miserable son's life ended up. As such, he commanded the waves to bring his son to the sea where he was "drowned in and offered to it". Actually, Palaemon tied Cheol-Su's life to the sea in order to not only save him from dying and his medical complications, but also give him a surge of strength to avenge his dead family. In exchange, however, if Cheol-Su stayed too far away from the sea, he would slowly grow weaker and eventually die.
As Cheol-Su resurfaced from the bottom of the sea, the South Korean pirates from before caught sight of him and hauled him to their yacht. When he woke up and found out he was in the yacht with those who raided his village, he knew he had to lay low before turning against them. While aboard, he met hostage-turned-pirates, Yeo Kyung-Tae and Park Hyun-Ki. They were twelve and fifteen years old, respectively, and had ran away from their own homes only to be kidnapped by the so-called Kkangpae or the South Korean mafia. Their gang of pirates, called as the Gangchi or "Sea Lions", were allied with the said mafia.
It wasn't long before Cheol-Su learned the ways of the Gangchi, especially when it came to raiding towns and villages across the islands in South Korea. Everything that they wore, ate, and used were taken from their victims. If slaying them was necessary, they would do so, but Cheol-Su was pretty reluctant. They called their way of living as "paying the iron price". Doing these kinds of crimes, aside from a lot others, were all parts of his act in a quest for revenge, waiting for the right time to strike.
A year later, the Gangchi squared off against their rivaling pirate gang, the Taepung. Cheol-Su, Kyung-Tae, and Hyun-Ki, now the best of friends, tried to smuggle out one of the yachts but were drugged and incarcerated by the crew members. As a result, the Taepung got hold of three new slaves to be sold to a wealthy drug dealer, Choi Bon-Hwa, at a price of almost 500,000 South Korean won per head in Busan.
Aside from drug trafficking, Cheol-Su, Kyung-Tae, and Hyun-Ki were exposed to a lot more crimes under Bon-Hwa's command. Having background on crimes such as larceny, fraud, and even murder, the three teenagers didn't have much difficulty doing what was asked of them. They were the least expected to do such things for they were children. Although the three were known throughout Bon-Hwa's affiliates, their true identities were only known to him.
Nevertheless, Cheol-Su and Kyung-Tae still had room for doubts on what they were doing. Cheol-Su's path was totally set aside after being sold by the Taepung, and now lived as nothing but a slave working for a greedy, fat hustler. Being the eldest, Hyun-Ki tried convincing Cheol-Su and Kyung-Tae that it was no use escaping because Bon-Hwa had a lot of connections to other organized crime groups, both local and international. However, his two friends weren't easily swayed. Ever since then, Hyun-Ki became cold and distant to them, and was easily manipulated by Bon-Hwa.
Their activities remained as is until a chimera went bursting into Bon-Hwa's large bungalow a year later. During the carnage, Cheol-Su and Kyung-Tae used the opportunity to finally kill Bon-Hwa. They planned to fake their deaths, attribute their master's death to the chimera attack, and escape. Hyun-Ki, however, threatened to expose their secrets if they ever did leave. If it weren't for the chimera killing him, Cheol-Su would have done the honors. The chimera knocked the two boys unconscious, until a satyr arrived at the scene to kill the monster. The satyr brought the two demigods to Camp Half-Blood, where they were claimed and given briefing on the whole Greek god thing.
Initially unhappy at their stay, Cheol-su and Kyung-Tae found hope when they met a certain child of Hermes who knew his way around computers. With the demigod's help, they started searching for the Gangchi and Taepung's whereabouts and activities.
With about two million South Korean won they stole from Bon-Hwa's vault during their escape, the child of Hermes set up a dead pool of sorts. Using a coded list of the Taepung's current members, they intended to lure the Gangchi into killing their rival pirate gang for the bounty. When they had communication with the Gangchi, they used the monikers Sang-Eo and Yuseong, respectively. Once the Taepung has been eliminated, Cheol-Su and Kyung-Tae would ambush the Gangchi.
After setting up the plan and training at camp for several months, they went back to South Korea. The Taepung's yachts were last seen scouting the island of Ulleung-do. With audio tapes sent to the Gangchi, Cheol-Su and Kyung-Tae instructed them to go there. Before payment was made, the Gangchi needed visual confirmation of their kill. Nonetheless, the two secretly followed them.
Once the Taepung was ambushed by the Gangchi in Ulleung-do, Cheol-Su and Kyung-Tae joined the fight. One by one, members of both pirate gangs fell. The air reeked not only of blood, but also of retribution. It was the two demigods' moment of glory, especially to Cheol-Su, who had waited years to get back to the people who wronged him and his family. He practically enjoyed the savage massacre, having better control of his powers now. However, his thirst for blood ended abruptly when he saw Kyung-Tae collapsing to the ground, already dead from a gunshot.
Now fighting for his best friend, Cheol-Su killed the last of the pirates and tried reviving Kyung-Tae. Unfortunately, he wasn't able to do so. In the end, he went back to camp, his morale diminished by the loss. Unbeknownst to him, Kyung-Tae was revived as a star spirit, awaiting his return.