Kali's earliest appearance is that of a destroyer of evil forces. She is the most powerful form of Shakti, and the goddess of one of the four subcategories of the Kulamarga, a category of Tantra. She destroys the evil in order to protect the innocent. Over time, Kali has been worshipped by devotional movements and tantric sects variously as the Divine Mother, Mother of the Universe, Adi Shakti, or Adi Parashakti. Shakta Hindu and Tantric sects additionally worship her as the ultimate reality or Brahman. She is also seen as the divine protector and the one who bestows moksha, or liberation.
Kali is the feminine form of "time" or "the fullness of time" with the masculine noun "Kala' and by extension, time as "changing aspect of nature that bring things to life or death." Other names include Kaalratri ("the black night"), and Kalika ("the black one").
Kali appears in the Death of the Mahabharata. She is called Kaalratri (literally, "dark blue night") and appears to the Pandava soldiers in dreams, until finally, she appears amidst the fighting during an attack by Drona's son Ashwatthama.
In Kalis most famous legend, Ambika and her assistants, the Matrikas, wound the demon Raktabija, in various ways and with a variety of weapons in an attempt to destroy him. They soon find that they have worsened the situation for with every drop of blood that is dripped from Raktabija he reproduces a clone of himself. The battlefield becomes increasingly filled with his duplicates. Ambika summons Kāli to combat the demons. The Devi Mahatmyam describes -
Out of the surface of her (Ambika’s) forehead, fierce with frown, issued suddenly Kali of terrible countenance, armed with a sword and noose. Bearing the strange khatvanga (skull-topped staff), decorated with a garland of skulls, clad in a tiger's skin, very appalling owing to her emaciated flesh, with gaping mouth, fearful with her tongue lolling out, having deep reddish eyes, filling the regions of the sky with her roars, falling upon impetuously and slaughtering the great asuras in that army, she devoured those hordes of the foes of the devas.
Kali consumes Raktabija and his duplicates, and dances on the corpses of the slain. In Devi Mahatmya version of this story, Kali is also described as a Matrika and as a Shakti or power of Devi. She is given the name Chamunda, i.e. the slayer of the demons Chanda and Munda. Chamunda is very often identified with Kali and is very much like her in appearance and habit.!
Jai Maa Kali