Star Master Cultivation Biography

My name is Jiang Xu and I am a time traveler, but why is the world I travel through so strange? [People can only live in the star field and be protected by the star master. ][There is a dark realm outside, and there are endless night beasts inside, and they have all kinds of strange abilities. ] [If a mortal wants to become a star master, he needs to absorb starlight, gather it in the Dantian, and open the star orifice. ] [Why are there qualifications divided into A, B, C, etc., Upper, middle and lower grades to become a Star Master? ] ...