Durga Saptashati — Mahishasura Mardini Katha
The demon Mahishasura, after severe tapas, received a boon that no man or god could kill him. With this power, he conquered the three worlds and drove the gods from heaven. The gods, led by Brahma, Vishnu, and Shiva, concentrated their divine energies and from this combined light emerged Devi — the Goddess Durga. For nine days and nights she battled Mahishasura and his armies, and on the tenth day, Vijaya Dashami, she slew him.