The Nascent Soul is the true self.
Though Zhang Chulan is a dominant consciousness, in front of the true self, he is just an insignificant segment of consciousness.
In cultivation, what's referred to as condensing the Primordial Spirit involves the main consciousness slowly permeating the true self as a baby, allowing it to gradually grow into oneself and then merge with the true self.
Only then can the heart and self become one.
However, if the growth of the Nascent Soul differs from the main consciousness, creating a separate self, or is disturbed, then that's a big problem, as the main consciousness will ultimately be extinguished by the Nascent Soul.
The reason...
It's clear just by comparing the size of the Nascent Soul with the body of Zhang Chulan, the dominant consciousness—it would be an overstatement to even call Zhang Chulan's dominant consciousness a surface level one.
