How does Chapter 18 of the Shri Sai Satcharitra describe the nature of the Sadguru?

Chapter 18 describes the Sadguru in exalted terms, calling him the "supreme Eternal one" and the "Ruler of Maya." The text explains that through experience, the Sadguru shows the world to be an illusion and is the ultimate teacher of the knowledge of the Self. A powerful metaphor is used: just as a salt doll entering the ocean can never return, so too is the case for one who approaches the Sadguru, signifying complete dissolution into the divine. As stated in this chapter, the Sadguru effortlessly points out the "Unperceivable One" to his devotees.