Based on the teachings in Chapter 16, what is the ultimate purpose of the Sadguru's incarnation, and how is his power described?

Chapter 16 of the Sai Satcharitra explains that the Sadguru, though being the "King of Yogis" and beyond attributes (Gunatita), has taken a physical body for a specific purpose: to help others and to uplift the poor and lowly. His immense power is described metaphorically, with the "sharp blade of the sword of Knowledge" shining brilliantly in his hand. According to this chapter, the mere sight of this hand raised to strike is enough to make the entire tree of worldly existence (Bhav-vriksha) tremble in fear, signifying his ability to destroy worldly attachments for his devotees.