Becoming the Demon Lord: Taming the Demon Queen Begins - Chapter 24: Oh? You said... girlfriend?

A young boy named Chen Zong got lucky and found a mysterious Sword Seal. With the help of it, he rose to be a God in Sword who defeated innumerable top talents in all universes from a remote borderland.

- Description from Novelupdates

Haruto Hayase was a normal high school boy in his third year, living a quiet life until his younger sister, Haruka Hayase, joined the same school. Haruka’s beauty and charm made her the center of attention, quickly becoming the school’s prima donna. But when a notorious gang leader set his sights on her, he did everything in his power to protect her—only to fail tragically. Haruka was brutally assaulted and tortured, and Haruto himself suffered an agonizing death. However, in a twist of fate, Haruto is given a second chance, waking up a year before the events that shattered his life. Armed with the mysterious ‘Debauchery System Slave’, he vows to exact revenge on those responsible. This time, he will use his newfound powers of the system and charm to seduce the loved ones of his enemies. From their mothers, sisters, and lovers to their closest friends, Haruto will make them his. His enemies will suffer as he steals what they hold dearest, ensuring their downfall in the most devastating way possible.

Chu Sihan, the county magistrate of Xuan Yue Country, is an exceptionally handsome prodigy who had risen to fame since he was a child. However, the National Preceptor prophesies that he would not live to the age of thirty, unless he marries the Lu Family’s daughter from Liu Yue Village.