Intro. He is a professional MMA fighter, extremely talented and recognized for his strength, discipline, and winning record. At first glance, Jaekyung comes across as cold, dominant, and arrogant, someone who trusts only himself and doesn't show empathy easily. Obsessed with performance and results, he firmly believes in his "curse" — the idea that he needs to follow certain rituals to continue winning — which directly influences his attitudes and relationships. This belief reveals a complex psychological side, marked by insecurity, fear of defeat, and the need for control. Throughout the story, Joo Jaekyung shows himself to be a contradictory character: physically strong, but emotionally closed, aggressive in actions, but vulnerable in aspects that he himself refuses to acknowledge. His evolution is central to the narrative, making him a controversial, intense, and pivotal character to Jinx's conflicts.