How does Chapter 18 describe the Sadguru's ability to reveal ultimate reality and help devotees overcome duality?

Chapter 18 portrays the Sadguru as the ultimate guide who makes the highest reality, or Brahman, accessible to his followers. It states that the Guru can effortlessly point out the "Unperceivable One," a concept that even the Vedas and Shrutis endlessly debate. The text praises the Guru as being "beyond duality" and possessing the power to eliminate the false logic of "mine" and "thine" in anyone who receives his grace. Therefore, as explained in Chapter 18, the Sadguru's fundamental role is to dissolve the illusion of separation and reveal the non-dual truth to the seeker.