The cultivation system as character development
The most important principle of cultivation fantasy craft is that the cultivation system should externalize the protagonist's inner development rather than replace it. Each stage of cultivation should correspond to a genuine transformation in who the character is: their relationship to power, to others, to their own limits. The breakthrough that requires the protagonist to let go of a deeply held belief, to accept a painful truth, or to make a genuine sacrifice is the breakthrough that resonates. The breakthrough that is merely technical, requiring only the accumulation of sufficient resources or the application of sufficient effort, is the breakthrough that produces a stronger character without producing a more interesting one.