This Is the Time to Travel to the World of Cultivating Immortals

[Traditional fantasy, first become a mortal, then become a demon, no system] [Front: You won't kill this? Back: You'll kill all of this?] What is an immortal? What is a demon? There is no distinction between good and evil, it's just that the stance and the path we seek are different! I will fight against the nine heavens with one person and kill until there are no more immortals in the world! It's just that why other people who travel through time are bound to the system, have invincible qualifications, and have a heaven-defying physique, but why do I have nothing...