Based on these passages, what is the ultimate nature of Sai Baba and why did he appear in Shirdi?

According to Chapter 43, the ultimate nature of Sai Baba is that of the 'complete Supreme Brahman.' He is described as a 'mass of bliss' who is 'beginningless and endless' and will 'remain unbroken even at the end of the universe.' The text clarifies that his appearance in Shirdi was not a conventional birth but a manifestation that occurred for a specific purpose: 'for the sake of the devotees’ protection.' His form was 'gathered by the past merits of devotees,' meaning he appeared in response to their collective devotion and need. After his task was complete, he merged back into his true, unmanifest form, becoming one with Brahman and filling the entire 'moving and non-moving world.'