Phenomenal and powerful episode here. The premise of the basis of the story that Ochou killed the family might be true. In fact, the dive into Ochou herself was great. She did everything to appease her mother because she was the only family she had. In a way you could say she killed herself, or rather her personality, and put a mask on to appease her, even if it is clear how selfish her mother is. Devoid of personality, she fell in love with the Masked Man. It feels very poetic.
It feels like that since Ochou is revealed to be the Mononoke, she must have killed herself. We see her handed the axe. As the Masked Man made Ochou believe that she killed the family as a way for her to get past her suffering. Though she was guided by Ochou in her Mononoke form. This leads to the prison that Ochou is in because she made that for herself to protect her. Even more so thinking that the Masked Man was the Mononoke for it to make sense for her and to be able to cope with it.
Then we are left with the final scene. It seems more likely that The Apothecary exorcised her. Unless we are to assume she came back to life, which seems like a stretch.
