The once cold and arrogant byakuya is now gone, he drowns himself in guilt, he has to change, he has to prove himself, he has to show that he'll be a nice person, but what can he do? (I headcanon that he joined inanimate insanity just to get away from his family and try to make some friends, despite his once cold, arrogant, and aloof demeanor, he wanted to be treated differently, he didn't want to be perfect anymore, especially after realizing that his family used him for money and profit)