Beneath the Dragoneye Moons - Chapter 586: Sing

“Mr. Qi Lin, may I ask how you thought about joining the entertainment circle from a sports student?”

“Uh, I said that I was there to deliver lunch boxes, do you believe me?”

- Description from novelbuddy

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.

In novels with a stud there is always a Senior Martial Brother like this:

In the early stages of the novel, his innate talent is high, his cultivation is good, his appearance is handsome, and he has an intelligent, cute younger Martial Sister as a fiancée.

In the middle stages of the novel, he is caught unprepared and defeated by a young disciple (the protagonist) in the sect who’s hardly remarkable at all. From then on, he falls from his godly altar and loses his brilliance. Even his young Martial Sister leaves him for someone else.

In the late stages of the novel, he continues to turn dark, going down the Demonic Path and becoming the major villainous boss. However, the protagonist still ruthlessly defeats him and his soul is eternally sealed.

Once Qin Mo opened his eyes, he discovered that he had become this Senior Martial Brother.

- Description from Novelupdates

Collecting legendary antiques, retracing the mysterious martial arts. From the moment he activated his cheat, Casio knew that he was no longer ordinary.[Legendary Antiques: Wind Elephant Ivory Pendant]Seventy years ago, in the North Flow Country of the Hong Li Federation, at the Wind Elephant Gate Youth Training Camp.“Li Wei, you are a coward! On the day your sister was brutally murdered, you were trembling in a corner! On the night of the Sect Destruction War, you disgracefully fled! During the many long years of revenge, you missed the opportunity again and again!”“Now let me teach you what bravery is, let me tell you how to turn suffering into your power. I hope at the moment you behead your enemy, you will remember: you are a man, an upright man!”The taboo era, hidden legends. A Foggy continent paralyzed by the sealed land. Countless brilliant antiquities wail in the ruins.I will witness your lost legends in the mist, the knights in the sky, the ghosts in the desert, the rats in the mud. The direction of sword fights points to the light, and flowers will grow where bullets fall. The winds of history will eventually sweep away the rubbish from the era's gravesite.