I remember the MCs was named He Huan--He is imprisoned because he hated the Wang Clan, was too arrogant, and failed to kill them while illegally using the sect resources--because apparently the mortal village was protected by the demons. He had a bright radiant sun physique which was extracted by Elder Tie, the punishment hall elder, to make a weapon and he slowly gave up on life. Then, demon lord Shura comes in and possesses the guy, he acts all subservient and humble in order to get released and implies that the prison was broken because his special physique was regenerated and sect leader supports him while Elder Tie still wnats to kill him.