POSSESSION: The Hidden Omega In All Alphas' Academy [BL] - Chapter 7 - : Truly Surreal

The main character is reborn as a character from a game he played in his previous life. This character falls into ruin along with the villainess, spending the last of their years together. A man named Kururi Helan.

In the near future, a space channel connecting the other world suddenly appeared on Blue Star, and a large number of other world monsters poured into the homeland where human beings depended for survival.

Human civilization has shrunk sharply and had to hide in the base city to survive.

Only warriors can lead human beings to open up living space and regain lost land.

However, martial arts requires talent, and not everyone can become a martial artist.

People with outstanding martial arts talent can not only advance quickly and break through limits, but also optimize their exercises and benefit future generations, and are admired by all mankind.

By chance, Lu Heng discovered that his martial arts talent could continue to evolve…

- Description from novelbuddy

In the age of the Great Liang Dynasty, the lives of the people were made convenient with steam-powered machines that run on a fuel named Violetstream Gold. Chang Geng, who lived in a small countryside village, shared a distant relationship with his mother while his stepfather was away most of the year round, and the only people he was close to were two little kids, the village teacher, and his yi fu – adoptive father. But his life was flipped upside down one day following the barbaric Man tribes’ invasion, and it turned out that his entire identity had been an illusion – not only was Chang Geng himself not the country boy he thought he was, but also his mother, his teacher, and even his beloved yi fu…

- Description from Novelupdates

Another entry in what you can call the Proto Harem Series: the books written before the Harem Series that take place in the same world.

It’s about a swordswoman whose student is captured, so she goes to rescue her.