Killer: My Killer System

[System + Immortal Cultivation + City + Time Travel + Rebirth + No Heroine] Mo Chen's family was destroyed, and his parents lost their way while fleeing with him. Their whereabouts were unknown, and he also ended his life in despair. When he woke up, he found that he was reborn eight days before his family was destroyed, and he also vowed to make the people who destroyed his family pay with their blood. And it just so happened that he also awakened the system to help him. . . . . . [This will not be used as the main plot at most 5 or 6 chapters will be written]