The division of martial artists and ninja levels at the Fusang Sword Saint Palace was something Ye Feng made a point of understanding in detail before setting out from the Northern Cloud Residence. They were broadly divided into upper, middle, and lower levels, with the lower-level martial artists or lower ninjas being the most basic. Above the upper-level ninjas is the Earth Level, above Earth Level is Sky Level, and above Sky Level is the Shadow Level.
As for the Shadow Level, their cultivation realm is roughly equivalent to the powerful beings of the Sacred Realm in the Xuanyuan Nation. It was only then that Ye Feng realized that when there was a disturbance, he had once visited Fusang, but his cultivation level was relatively low at the time, so he did not encounter a true Shadow Level powerhouse taking action.