Overview:
One hundred years ago, in the battle of Mirage Land, the fairy Tianjuan killed the Lord of Mirage with her own hands. However, Tianjuan's soul was incomplete and she lost her memory of the war.
After the war, Tianjuan came down to earth and to serve as the landowner in Cangshuo. She adopted the fairy pet Li Xiao, which looked like a little black bird. Then the war goddess and the little black bird teamed up to solve a case. Behind a series of strange murders, they found traces of the mirage monster returning to the land of Cangshuo! As Li Xiao transforms, Tianjuan discovers that there is a possible connection between her dead lover Shao Weili, Li Xiao, and the Lord of Mirage whom she killed...
(Source: iQIYI, Google translated)