My brother is a hitman

Xue Feng, a top-tier hitman who was once ranked third in the underworld's 'Yan Luo Hall' assassin organization, had grown weary of a life drenched in blood and violence. Determined to leave that world behind and turn over a new leaf, his only wish was to return to his hometown and protect his younger sister, Xue Lian, so she could live a peaceful life. Xue Lian worked diligently at a trading company, and Xue Feng simply wanted to rely on his own efforts to keep her away from trouble and give her a calm, comfortable existence. But what he never expected was that the trading company his sister worked for was nothing more than a human trafficking ring hiding behind a legitimate facade. The boss was secretly carrying out heinous, despicable crimes. When Xue Lian was tragically targeted and abducted by these vile criminals, Xue Feng was consumed with rage. The killer instinct of his former days came roaring back in full force. Fighting his way through countless obstacles and blood-soaked battles, he set out alone on a path to rescue his sister." If you want a more concise, cinematic-style version (like a movie synopsis), here's an alternative: "Xue Feng—once the third-deadliest assassin in the feared Yan Luo Hall—hung up his blades for good, seeking nothing but a quiet life back home with his sister Xue Lian. But when the trading company where she works turns out to be a human trafficking front, and she becomes the latest victim, Xue Feng's dormant fury explodes. The legendary killer returns, cutting a bloody swath through anyone who stands between him and his sister."