Tomodachi no Imouto ga Ore ni Dake Uzai - Volume 1, Epilogue

Ye Xiao was a superior cultivator in his previous life. The three factions of the realm kill millions of people every time they attempt to seize cultivation resources. Wealthy towns turn to wastelands in just a single night. They cover up their crime with an assertion that the towns were suffering from pestilence and disasters.

They forcibly hold all the resources for cultivation, monopolize all valuable practice materials, and keep outsiders from cultivating so that only their three factions could cultivate in the realm. Ye Xiao declared war against the three factions in retaliation for their actions. He fought alone and ended up dying in vain. However, he is reborn into the mortal body of a 16-year-old boy. He will use the powers he cultivated in his last life and slaughter his way back into the Realm. The story begins!

- Description from Novelupdates

“Alas, this life is a failure; let’s see what the next life holds.” ... “The second life has ended, calculating results... Final rating: C+. Rewards based on rating: You may choose to inherit one item from Constitution, Skill, or Talent. Please select?” “Hmm, I choose to inherit the Talent ’Dynamic Vision’.” “Talent inherited... Congratulations on achieving the following lifetime achievements: Innate Grandmaster; Blessing of Many Offspring (10/10)” Achievement rewards: Two random rewards. You may draw from Constitution, Skill, or Talent, or choose to upgrade Talent level. Please select? ... A reborn individual, in possession of the treasure ’Hundred Lifetimes book’, reincarnates within the Cultivation World, undergoing endless cycles of rebirth without the bloodline ending or the soul perishing! The family he established ten thousand years ago has now grown into a massive entity that spans the heavens. The disciple taken in casually eight thousand years ago ultimately became the founder of a Great Sect in the Immortal Realm. The pet raised three thousand years ago has evolved into an unparalleled Demon Saint of the Otherworld. ... I am Zhao Sheng, and I shall cultivate life after life until Ascension!

As his contract-marriage wife, she just wanted to fulfill the mission given by his mother—having a baby. They didn't love each other, so he always used contraception before they got laid. She had been obedient to him, only to find that he had gone too far! He actually didn't care about their child at all! She couldn't stand it anymore, so she handed him the divorce papers and left, noting: “The world is so huge that I can surely find a better man.”Looking down at her, he retorted, “Come on, your purse strings will tighten up first before you find anyone.”

agreed. He thought they might just talk, have a few drinks, and that nothing significant would happen. However, she invited him to a hotel, and they spent the night together.The next morning, she told him it was just a one-night stand and that they would probably never meet again. She said goodbye and left. Ronan also decided to treat it like that.The next day, at his college's hosting club, Ronan was given the responsibility of hosting that year's annual function, where they had invited a singer.When Ronan looked up at the singer, he was shocked—it was the same woman he had spent the night with. After checking her history and social media, he formed an impression of her. Every picture she posted was in revealing clothes, bikinis, or almost nude outfits.He concluded that she was just a promiscuous woman, likely driven by lust, and that she had probably chosen to spend the night with him simply because she found him handsome.Understanding this, Ronan decided to focus on his work. That morning, she had made it clear that it was just a one-night stand and nothing more. He would treat it exactly that way and carry out his responsibilities.Protagonist has System---No NTRIt's Harem, with many girls but The Singer is Main Heroine.