In Zhao Sheng's view, the so-called "Nine Steps of Tao" actually represents the Cultivator's mastery of the Taoist Law they practice!
This silk book might have been authored by a certain True Immortal with Great Ability, summarizing the cultivation below True Immortal as "Mortal Three Gates, Primordial Spirit Tribulation, and the most difficult Three Steps of Immortality".
The Mortal Three Gates need no elaboration, while the Primordial Spirit Tribulation refers to the Golden Core, Nascent Soul, and Divinity Transformation stages!
The Three Steps of Immortality correspond to the Returning to Void, Unification, and Crossing Tribulation three major realms!
From Returning to Void, a Cultivator is called a "Demi Immortal", having initially broken free from the Life Span shackles, with lifespan measured in tens of thousands of years, almost all are ancient monsters over millennia old!
