Another much earlier Puranic character associated with Kerala is Mahabali, an Asura and a prototypical just king, who ruled the earth from Kerala. He won the war against the Devas, driving them into exile. The Devas pleaded before Lord Vishnu, who took his fifth incarnation as Vamana and pushed Mahabali down to netherworld to placate the Devas. There is a belief that, once a year during the Onam festival, Mahabali returns to Kerala. The Matsya Purana, among the oldest of the 18 Puranas, uses the Malaya Mountains of Kerala (and Tamil Nadu) as the setting for the story of Matsya, the first incarnation of Vishnu, and Manu, the first man and the king of the region.