How does Chapter 18 describe the profound nature of a Sadguru and the effect of approaching one?

Chapter 18 portrays the Sadguru as the supreme, eternal one, the very truth of Brahman, and the 'Ruler of Maya' who reveals the world's illusory nature. The text uses a powerful metaphor to describe the transformation of a devotee. It states that if a salt doll enters the ocean, it can never return in its original form. Similarly, when a seeker truly approaches the Sadguru, they merge with the divine, losing their separate identity. As Chapter 18 explains, the Sadguru also makes the 'Unperceivable One,' which the Vedas debate endlessly, effortlessly accessible to devotees.