The evil of demons and ghosts all originates from human malice; the kindness of people can also transform the deepest resentment. The real evil is never the demons and ghosts, but the greed and malice deep in the human heart.
From the beginning, the protagonist just wants to live his own small life, to finally shouldering the responsibility of protecting the world. It explores the eternal proposition of "the greater the ability, the greater the responsibility" and the preciousness of ordinary life.
