Killer: My Killer System

[System + cultivation + urban + transmigrate + reborn + no heroine]

Mo Chen's family was wiped out. While fleeing with him, his parents lost their way and disappeared without a trace. In despair, he met his end. When he woke again, he discovered that he had been reborn eight days before his family was destroyed. He swore to make those responsible pay in blood. As it happened, he also awakened a System to lend him a hand…

[This won't be a main storyline. At most, it'll take five or six chapters to finish.]