Jin Kyulkyung was a handful in his teenagers years. He was the boy your mom and dad feared when you told them you got a boyfriend. He was the acclaimed bad influence, disrespectful, reckless, and all around a bad apple. He went through both boyfriends and girlfriends like they were collectibles only to break up with them a week or two later. His academic achievements consisted of shitty papers written at three A.M. in the morning that somehow got him all the way through Mahoutokoro. Not with excellent marks, but got him through regardless. After graduation, he met his sweetheart, his one and only, and his hardest catch.
Song Yeonghui came from a pure-blood family of the elite of the South Korean magical society who were hellbent on making sure Yeonghui got married to a respectable pureblood like the rest of them. Jin Kyulkyung kinda had other plans. Sure, he was pure-blood as well and his family was loaded, but he definitely didn't fit the requirement of "respectable". In fact, he was anything but it. His parents had given up on getting him married, just hoped that he stayed in his countless flings instead of marrying a muggleborn or half-blood. Then Kyulkyung and Yeonghui met and it was like the Jins' prayers had been answered. When the two finally started dating, Kyulkyung's parents were the ones pushing the relationship forward while Yeonghui's were the ones trying to hold it back. Eventually, the two families came to an agreement and forced their children to get married.
It worked out because by then, Kyulkyung and Yeonghui were well in love, but everything was a little rushed. For one, two years after getting married, they had started popping out kids. First came a boy and then a girl and then another boy and then two girls and then another boy. You'd think they'd stop after six, but in the current day, Yeonghui is pregnant with triplets. Ouch. Pay attention to that second boy, that's Kyulsoo. By the time Kyulsoo was born, the family had moved to Britain due to Yeonghui's career ventures. Kyulkyung paid the rent through less formidable jobs but the two still worked together as a fairly decent team to make sure all of their kids were well fed and taken care of.
Kyulsoo, given the English name Kaelan at the age of one, was an unusually quiet child, a stark contrast from his present day persona. He didn't cry much when he as born, didn't smile as much as his siblings, didn't show a lot of things actually. One thing he did do was develop faster than the rest. He learned how to talk and walk quicker then the rest of his siblings but it really was a waste because he didn't talk much regardless and he spent much of his time hiding away instead of playing with his siblings. From an early age, Kaelan had always felt out of place. At some point, he tried to integrate himself into the dynamic of his siblings and feel more connected to his family but no matter how hard he tried, he always felt like he could never break through. He was never the center of his parents' attention and rarely got recognition from anyone else either. At family reunions, no one paid attention to him, and he was just as invisible in school as well.
He was eight when he decided he had to make himself more interesting for people to pay attention to him, so he turned to dangerous activities. His first magical sign actually gave him this idea. Their father had made them a treehouse in the backyard of their large home in the English countryside. The treehouse itself was also a little big, supported by three trees. It was big enough to have a room for each child, as well as a middle play area. In this treehouse, Kaelan spent a lot of time by himself because no one really played with him or made an effort to get him involved in whatever was being done. So, he sought to entertain himself by climbing out of the window of his treehouse and up the rest of the tree. One time, his little eight-year-old self climbed so high into the tree that he couldn't figure out how to get back down. So, logically, he saw the only way down was to fall. Don't get me wrong, Kaelan's bright, but his decision making skills definitely need work. He fell from the tree and luckily caught himself on a pile of mattress that had previously been a pile of leaves.
Even this little stunt didn't garner too much attention from his parents. They knew all their kids would likely be magical, so when they heard about it, there wasn't a reaction at all. So the pattern continued. Kaelan would do ridiculous things to get his parents' attention and would end up to little to no results. No matter how hard he tried, he'd get a little slap on the wrist and would be back doing whatever he could to make his parents react somehow. Finally, after he pulled a stunt a little too big the summer before his first year at Hogwarts, his mother snapped and sent him to a correctional facility. For two weeks. That's all. If anything, he came out worse than what he had been doing before. He would've gotten a lot worse too if he hadn't been scouted by Silencio Records. His parents, too concerned with the rest of their children, could barely spare a second thought about it, so before he could even get half the question out, they were already signing the papers and pushing him out the door into SR's hands.
Kaelan gathered a following of friends at Hogwarts, half of which encouraged his dangerous activities, and the other half of which was genuinely concerned about his mental health. Neither really talked to him on a level of normal human being though. He was always the cool kid who'd climb up the wall and hang from the hallway's chandelier if you asked him. Not a living, breathing human being with emotions and insecurities and a desire to be paid attention to and loved. He realized it sooner than later he was never going to get what he truly wanted, so he began settling for himself again. Playing the cool troublemaker in front of his "Friends" and his family, and stayed himself, his inferior, insecure self in his lonesome. It was when he was second year that he started becoming interested in computer science. With no one else around to either encourage or discourage him from this newfound hobby, he dedicated himself to it, teaching himself how to program with the help of the Internet and how to hack with... less formidable sources.