How does Chapter 10 explain the power of the Sadguru in a devotee's life?

According to Chapter 10 of the Shri Sai Satcharitra, the Sadguru possesses immense power to transform a devotee's life. It states that by placing faith in the Guru's feet, He can change one's fate, poetically described as striking "a nail over the lines of destiny." The chapter further explains that the Guru serves as a boatman to help devotees cross the ocean of existence (Bhavasagar) and overcome the three types of miseries. By the Guru's sight alone, the knots of the heart are broken, attachments vanish, and both accumulated (Sanchit) and current (Kriyaman) karmas are destroyed, ultimately leading to liberation.