For Cultivators they call the normal ranking of F to SSSS, the ability form, because essentially it focuses on the ability, but what's amazing about cultivators is that despite being humans they can strengthen their bodies, and reach the truest potential of using their abilities.
Then they call the soul ranks, the soul form, which rely more on the strength of a soul, and since the soul ranks rely on tiers, they rely on the changing colour of the spirit which is their soul to determine which tier they are at.
Their spirit have three forms and their last form being the transcendence form, a state in which the soul manifest physically outside the body breaking the very foundational law placed in all the realms that state the soul with a body can't separate by the power or will of their owner.
Sorry for the late update.