Gao Wu: I Have Nine Volumes of the Unnamed Heavenly Book

[Physical time travel + marriage change + emotionlessness (multiple male protagonists) + urban martial arts] In the previous life, science and technology developed to its extreme, and classes gradually became stricter, gradually forming the upper and lower people. The upper people lived on the land, while the lower people hid in the sewers to survive... However, the servants hiding in the sewers formed a resistance army...