A/N: this headcannon might be triggering for some of you, if you don't want to read the headcannon you can skip forward but if you do want to look at the headcannon then proceed with caution.
🚫triggers: self hate/self pity, low self esteem, low confidence, insecurity, paranoia, insomnia, loneliness and depression.🚫
The only reason why he acted the way he acted was because he never had any confidence in himself and he always hated himself for it. When alone by himself, byakuya would feel this insecurity about his well-being and how does even have the ability to take care of himself. His insecurities made him feel paranoid and terrified about his self esteem that it even makes him stay awake at night in which causes his insomnia to rise even when trying to sleep at night. Recently, he was able to manage his past issues but he ended up gaining this loneliness because he didn't even bother to make friends since he was in such a dark place at the time so this caused his depression to rise every time he felt lonely. Present day, he decided to act the opposite of the way he acted before he was this super nice and caring person but now it was time for a change even though he knew it wasn't a good idea to be mean and conniving but he had no choice so he just went it.