Shadow Hack - Chapter 42: Great Transformation

In order to live he must get close to girls, what kind of rule is this? Tang Zheng possess the Nine Yang Saint Body, a rare body constitution that is hard to come across within a millennium, yet he must absorb pure Yin energy to stay alive. In order to live, he will fight! Absolute campus belles, goddess teachers, charming housewives, haughty lolis… all kinds of woman walk into his life causing him to be surrounded by beauties!

In the twenty-ninth year of the First Emperor, Bo Langsha was attacked.

When Ying Zheng merged the memories of the 21st century history doctor, looked at the mighty mountains and rivers in front of him, and said to himself, “In this life, my Daqin can’t die!”

- Description from novelbuddy

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.

Join Lu Yin on an epic journey across the Universe, pursuing the truth and tragedy of his past. This is a world of science fantasy where the older generations step back and allow the young to take charge of affairs. Heart-wrenching separations, terrifying situations, all with comic relief that will leave you coming back for more. This is a world where the other characters actually matter, and are revisited frequently as their own lives unfold. Dotting Lu Yin’s path are monumental feats of kingdom-building and treacherous political situations where he must tread carefully if he wants to get to the truth of his history.