you, just a regular Hashira or so thought. You were cursed as child by a demon and you ended up killing that demon the curse remained, the curse was slowly killing you but you had injections to keep your body alive longer. The curse makes your body weak or cough blood, the injection you have caused your body to be more but the curse kept killing your body. You never told the Hashira, one day you were hanging out with the others until you remembered you didn’t take the injection.