Complex sentence: He is later revealed to be Orochi's self before he is the demon he is now, as long before the series starts, Yinglong had rebelled against the Shangdi after being fooled by Mae Tamamo into believing that he had controlled demons.
Split into simpler sentences: He is later revealed to be Orochi's self before he is the demon he is now. Long before the series starts, Yinglong had rebelled against Shangdi after being fooled by Mae Tamamo into believing that he had controlled demons.