The cultivation of the Form Synthesis Stage was mainly based on the degree of integration.
If the body and Nascent Soul's fusion rate was within 30%, it was the early stage of Body Integration.The body and Nascent Soul's fusion rate was between 30% to 60%, which was the middle stage of Body Integration.The fusion between the body and the Nascent Soul was between 60% to 90%, which was the late stage of Body Integration.When the fusion between the body and the Nascent Soul was between 90% to 100%, it was the Perfect Body Integration!
Every 10% fusion rate was a small level. 30% to 40%, 60% to 70%, 90% to 100% were the transformations between the big levels.
Perhaps it could also be expressed as a percentage. Every ten percent of the fusion between the body and the Nascent Soul was a small bottleneck, and thirty percent, seventy percent, and ninety percent were the dividing lines of the three major bottlenecks.