While slaying Andhakāsura (Andhakasura), Mahādeva (Mahadeva) created out of his body innumerable Mātṛkā (Matrika; a kind of lesser female deities) in order to get their assistance in the slaying of the Asura.  Ekavīrā (Ekvira) (Ekavira) was one of these Mātṛkā.