Of course, the battle corpse sect's status in the underground world couldn't be compared to the tyrant's blade school's status in the true spirit sect. However, Zhao Hai's status in both sects wasn't low.
The reason why Zhao Hai was able to gain a foothold in the underground world so quickly and even become a true disciple of the battle corpse sect was because the first Earth world was different from the true spirit world.
In the true spirit world, no matter which sect it was, the conditions for accepting disciples were very strict. Moreover, there were also very high requirements for the character of the disciples. For someone like Zhao Hai, whose origin was unknown, no sect in the true spirit world would accept him as a disciple. Even devil cultivators and evil cultivators, who were very close to ghost cultivators, had many requirements for their disciples. Not just anyone could join their sect.
