Rising up from a Nobleman to Intergalactic Warlord!! - Chapter 176

In a world fractured by conflict and haunted by shadows of the past, Kokushibo—the first Upper Moon demon—meets his end, only to awaken in a new life. Reincarnated as Crimson, a child born into a different family, he carries the memories of a past he cannot escape. Burdened by centuries of guilt yet indifferent to the present, he resigns himself to duty—until an unexpected bond with his newfound family begins to thaw his hardened heart. As he struggles between the weight of his past and the weight of the new life, Crimson must decide whether he will remain shackled to his former sins or embrace the possibility of peace.

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!

- Description from Novelupdates

She was drugged by her ex-boyfriend and had her first night with a mysterious man.

A back-to-basics(?) monster evolution novel.