Synthesizing the various descriptions in the text, what is the ultimate role of the Sadguru in a seeker's life, from overcoming illusion to attaining self-knowledge?

Chapter 18 portrays the Sadguru as the complete guide for a seeker's spiritual journey. The Guru is hailed as the 'Ruler of Maya,' who reveals the world's illusory nature and helps the devotee transcend the egoic concepts of 'mine' and 'thine.' By bestowing grace, the Sadguru effortlessly points out the Unperceivable Brahman, a truth that even scriptures debate. Ultimately, the Guru is described as God manifest and the sole teacher of the knowledge of the Self, leading the devotee to a state of complete absorption, much like a salt doll dissolving into the ocean.