A god incarnates to save a corrupt world
In the epic, the celestial being Thötpa Gawa is persuaded by the gods and Padmasambhava to be reborn as a human, Gesar, specifically because the world has fallen into demonic corruption and war that only a divinely-sourced hero can purge. He is born into poverty and mockery before his royal destiny is revealed, winning the kingdom of Ling through a rigged horse race he was fated to win.