My Unexpected Path To Immortality

After journeying to a world starved of spiritual energy, he stood as an ordinary individual.  
Yet, he acquired the 'prodigal cultivation' system, rising to headmaster of a decrepit academy in a forgotten corner.  
Despite his mundane beginnings, this system unlocks unprecedented potential, challenging the norms of a world where power is a rare commodity.  
Now, as he navigates the complexities of his new role, a deeper mystery unfolds: why was this world's spiritual energy depleted, and what secrets does his system hold that could change everything?