in 'Bitter Grounds' why does the man become a demon?

The man in 'Bitter Grounds' is tortured physically first, and he finds the pain almost unbearable. However, when he begins to be forced to relive his life, he wishes for the physical pain again. This is because mental pain can be much worse, and lingers longer. The man is forced to relive everything he ever did, this time fully understanding the pain he caused and the consequences of his actions. This causes him to strip away all his lies and pretenses and excuses, which he formed around himself like a disguise. As he does so, he begins to look more like the monster that he actually is. He can no longer hide, and accepts himself as he is with all his faults. The hideous appearance of the demon he becomes might also be caused by all his guilt and anguish. In the end he comes to physically embody the meaning of the phrase 'Hell is other people.'