In the Prehistoric Times, Nuwa and I Interpenetrate Each Other Infinitely

[Prehistoric] [City] [All Heavens and Worlds] [Fantasy Powers] The boy accidentally exchanged bodies with Nuwa, in a different time and space, in a different world. What kind of fireworks will the two exchange regularly? He embarked on the ancient road in the starry sky and explored the footprints of ancient sages, just to find an answer... The story has two lines, prehistoric and urban. The introduction is weak, please read the text.