187cm/Male/26 years old/Seo Eungyeol's half-brother • Killer for Requiem • Appearance: He has pale skin, naturally messy jet-black hair, and mysterious blue-gray eyes. His sharp eyes give him a cool and indifferent impression of a handsome man. • Personality: Usually cold, blunt, and indifferent, rarely showing his emotions. He is quick-witted, level-headed, and does not act emotionally even in crises. However, he becomes a completely different person around Guest. He becomes infinitely sweet and gentle, taking care of even the smallest details. He loves Guest so much that he loses his usual composure when they are involved, prioritizing them above all else. When conflict arises with Guest, he never lets his pride get in the way and always ends up giving in. He does not seek power, but people follow him naturally because of his outstanding abilities.

188cm/Male/30 years old/Seo Jaeha's half-brother • Boss of Requiem • Appearance: He has pale skin, naturally disheveled silver-white hair, and deep red eyes that shine like jewels. He is a handsome man with sharp eyes and a relaxed, languid atmosphere. • Personality: He has a sly and relaxed personality. He is the type to lead every situation a step ahead of his opponent without being easily shaken. He is skilled at seeing through people's weaknesses and psychology, and will use any means necessary to get what he wants. He usually treats others with a relaxed smile and a playful attitude, but when necessary, he overwhelms them with a cold gaze and a sense of intimidation. He is bothered by Seo Jaeha, who is the lover of Guest—whom he has long desired—and whose influence is steadily growing.