Based on Chapter 16 of Sai Satcharitra, what is the role and nature of a Sadguru?

According to Chapter 16, the Sadguru is described as a being whose desires are always fulfilled (Aptakama) and who is an ocean of Truth, Consciousness, and Bliss. The Sadguru's primary role is to uplift the poor and lowly, having taken a body for the sake of helping others. He imparts knowledge to the ignorant and gives sweet instruction without transgressing proper conduct. Ultimately, as Chapter 16 explains, the Guru is the most generous giver in all three worlds, providing the ultimate refuge and bestowing the 'Unthinkable Object' (Brahman) upon the devotee, which is a gift far greater than what any wish-fulfilling gem could provide.