Durga came to Earth on the invitation and prayers of the people who were being harassed . She came down in her form of Mahisha Mardini or the slayer of the Buffalo which has ten hands holding ten different weapons given to her by the various Gods. She came riding her mount the Lion on the invitiation of her devotees. On the eighth day of the Sukla Paksha in the month of Ashwin she arrived on Earth.
On the ninth day the battle ensued with Mahishasura and the battle continued through the night.
The demon hid easily among Buffaloes by taking their form . But Durga cut off its head to reveal the Demon and eventually on the tenth day or on Vijay dasami she slayed Mahishasur with the help of her mount the Lion.
A brief of Mahishasura-Durga Battle
Armed with incredible powers, Maa Durga reached Alkapuri . Durga and her lion roared in unison. The roar shook the throne Mahishasura was sitting upon. The floor trembled. Mahishashur flew into rage. He called out to his chief commander, “Go and find out what that roar was!”
The commander and his demon soldiers departed and found Bhagwati Durga at the city gate. They asked who she was. Durga replied that she was the death for Mahishasur. She asked the commander to tell his master that he should vacate Indra throne and run away or get destroyed. The soldiers went back to the court and delivered the message of Durga to Mahishasur. Mahishasur rose up in fury and thundered, “Let me see the silly woman thing. Come.”
Mahishasur arrived to face Durga with a large demon army. The sight of Durga surprised him. He said, “Dear beauty, those slender hands of yours are not for weapons. I am new Indra, Mahishasur. Marry me and rule the heavens. I promise to make you my principal queen.”
The demon talk made Durga explode in anger. She roared her challenge, Mean demon! I come as your death, Take this!’ Durga threw Her trident. The demon evaded it and guffawed. He shot fiery flames at Durga. Durga blew away the flames which fell on the demons turned into flamelets. The demons ran around to escape from the falling fire balls.
It annoyed Mahishasur….