Once there was a rakshasaa named mahisha who gave lot of troubles to devas and saadhus. So they turned to Shiva who advised all the devas to release their shaktis (spiritual powers) locked within their bodies. The shaktis of the gods emerged in female forms
Shivani from Shiva
Vaishnavi from Vishnu
Brahmani from Brahma
Aindri from Indra
Kaumari from Kumara.
