Bell

Bell is the former owner of the Black Seat, which is now occupied by Kim Hajin. He is also the one who killed the Chameleon Troupe's ex-boss, Yi Yeonjun. As such, Boss hates him deep to the bone and seems to want him dead more than anything. Yet, it has recently been revealed that he feels deep pain when thinking of how he murdered his "best friends," meaning he still considered them as important beings to him.