Chandi - Cuttack, Odisha, India
|Mantra||ॐ ऐं ह्रीं क्लीं चामुण्डायै विच्चे
oṁ aiṁ hrīṁ klīṁ cāmuṇḍāyai vicce
Chandi (Sanskrit: चण्डी, Caṇḍī) or Chandika or Ran-Chandi (Caṇḍīka) is the supreme Goddess of Devi Mahatmya (Sanskrit: Devīmāhātmyam, देवीमाहात्म्यम्) also known as Chamunda or Durga as mentioned in Durga Saptashati. Chandi is described as the Supreme reality who is a combination of Mahakali, Maha Lakshmi and Maha Saraswati. Later in the Murti Rahasyam she is described as Maha Lakshmi with eighteen arms (Ashtadasa Bhuja Mahalakshmi) bearing weapons.
Caṇḍī or Caṇḍīika is the name by which the Supreme Goddess is referred to in Devi Mahatmya. According to Coburn, "Caṇḍīika is "the violent and impetuous one". In the light of the primacy of this designation of the goddess, it is striking that the word Caṇḍīka has virtually no earlier history in Sanskrit. There are no instances of its occurrence in the Vedic literature we have surveyed. The epics are similarly barren: neither the Ramayana nor the Mahabharata give evidence of the epithet, although in one of the hymns inserted in the latter Caṇḍa and Caṇḍī are applied to the deity they praised."
The designation of Chandi or Chandika is used twenty-nine times in the Devi Mahatmya, which is agreed by many scholars to have had originated in Bengal, the primary seat of the Shakta or Goddess tradition and tantric sadhana since ancient times. It is the most common epithet used for the Goddess. In Devi Mahatmya, Chandi, Chandika, Ambika and Durga have been used synonymously.
Goddess Chandi is associated with the 9 lettered Navakshari Mantra.It is also called Navarna Mantra or Navavarna Mantra. It is one of the principal mantras in Shakti Worship apart from the Sri Vidhya Mantras. It customary to chant this mantra when chanting the Devi Mahatmya.
The origin of the Goddess is given in the second chapter of Devi Mahatmya. There are various more stories regarding the incarnation of Devi Chandi or Chandika.
She is considered as Kaatyayini (Durga) itself, who had killed Mahishasura as well as Shumbha Nishumbha  "The great Goddess was born from the energies of the male divinities when the gods became impotent in the long-drawn-out battle with the asuras. All the energies of the Gods became united and became supernova, throwing out flames in all directions. Then that unique light, pervading the Three Worlds with its lustre, combined into one, and became a female form."
"The Devi projected an overwhelming omnipotence. The three-eyed goddess was adorned with the crescent moon. Her multiple arms held auspicious weapons and emblems, jewels and ornaments, garments and utensils, garlands and rosaries of beads, all offered by the gods. With her golden body blazing with the splendour of a thousand suns, seated on her lion vehicle, Chandi is one of the most spectacular of all personifications of Cosmic energy." 
In other scriptures, Chandi is portrayed as "assisting" Kali in her battle with demon Raktabija. While Kali drank Raktabija's blood, which created new demons from his own blood on falling on the ground; Chandi would destroy the armies of demons created from his blood and finally killed Raktabija himself. In Skanda Purana, this story is retold and another story of Chandika killing demons Chanda and Manda is added.
According to Markandeya Purana, when Indra and the other gods were praying to Goddess Mahasaraswati, to give them relief from the atrocities of Demons Shumbha and Nishumbha, Goddess Parvati (Maha Gauri) happened to hear their prayers. Out of curiosity, She asked them that whom are they addressing to in their prayers. From the body of the Goddess, a female came into existence and that was Devi Chandika. Chandika was also addressed as Ambika. Her actual name is believed to be Chandraghanta, one of the nine forms of Durga i.e. one of the Navdurgas. She has a third eye, through the eyebrows of which, Goddess Chamunda had manifested to kill demons Chand and Mund; and later, the great demon Rakthbeej too, was killed by Kali. Chandika had slain demons Dumralochan, Shumbha and Nishumbha.
According to Matsya Purana and as shown in one of the best known Indian TV serials Om Namah Shivaya, Goddess Parvati had done penance to please Lord Brahma. And as a reward for the penance, She requested for the recovery of her fair complexion, as She had become dark by Shiva's magic. Brahma gave the desired boon and the darkness of the Goddess got separated from her and took the form of another Goddess. That Goddess was considered as the daughter of Parvati and as she had taken birth from the Kaushik (dark cell) of her mother, she was named Kaushiki . Kaushiki had incarnated for the killing of the demons Shumbha and Nishumbha, who had got a boon that they would be killed by anjanmi (unborn) girl. And as Kaushiki had not taken any biological birth from her mother, She was the Ajanma girl according to the boon; and also she had supernatural powers, being the daughter of Goddess Shakti i.e. Parvati. Parvati, being a concerned mother, took part in the war against the demons. Henceforth, Parvati incarnated as Chandika, Chamunda and Kalika to kill the demons Dumralochan, Chanda & Munda and Rakthbeej respectively. These demons were sent by Shumbha and Nishumbha, who were finally killed by Kaushiki in her divine form. After the war, Kaushiki got merged into the body of her mother.
It is also believed that the extremely white skined beautiful goddess Kaushiki came into existence from Maha Gauri Parvati. Due to this, Parvati turned dark. Goddesses Lakshmi and Saraswati appeared there and bestowed their powers to Parvati. Hence, Parvati got transformed into Goddess Chandika, who firstly killed the demons that created havoc all over the earth. Then, She assisted Kaushiki in the war against Shumbh-Nishumbh. Chandika confronted the demons Chand and Mund sent by Shumbh and Nisumbh, during which Goddess Chamunda manefisted from the eyebrows of her third eye, who killed Chand and Mund. Later, Chandika killed Nishumbh and then while battling the great demon Rakthbeej, Chandika tranformed in Mahakali to kill the demon by drinking his blood. Hence, Chandika is considered as Parvati, Kali & Chamunda and is also considered as the mother of Mahasaraswati Kaushiki.
Chandi Homa (Havan) 
Chandi Homa is one of the most popular Homas in Hindu religion. It is performed across India during various festivals, especially during the Navaratri. Chandi Homa is performed by reciting verses from the Durga Sapthasathi and offering oblations into the sacrificial fire. It could also be accompanied by the Navakshari Mantra. Kumari Puja, Suvasini Puja also form a part of the ritual.
The dhyana sloka preceding the Middle episode of Devi Mahatmya the iconographic details are given. The Goddess is described as eighteen armed bearing string of beads, battle axe, mace, arrow, thunderbolt, lotus, bow, water-pot, cudgel, lance, sword, shield, conch, bell, wine-cup, trident, noose and the discus (sudarsana). She has a complexion of coral and is seated on a lotus.
In some temples the images of Maha Kali, Maha Lakshmi, and Maha Saraswati are kept separately. The Goddess is also portrayed as four armed in many temples.
Temples devoted to Chandi are located in many places including the following:
- Gandaki Chandi, Gandaki near Pokhara, Nepal. (Shakti Peethas)
- Mangal Chandika, Ujjaani, West Bengal. (Shakti Peethas)
- Saptashrangi Temple, Vani, (Maharashtra). (Ashtadasa Bhuja Mahalakshmi)
- Mahalaxmi Temple, Mumbai (Maharashtra). (Three separate images).
- Hemadpanthi Chandika Devi Mandir, Katol (Maharashtra).
- Vaishno Devi temple, Khatra, Jammu and Kashmir. (Three Pindas (stones)).
- Katak Chandi Temple, Cuttack, Odisha. (Four armed).
- Ashtadasa Bhuja Mahalakshmi temple, Skandhashramam, Salem, Tamil Nadu.
- Mangal Chandi temple, Guwahati, Assam.
- Mangal Chandi temple, Chandithala, Kolkata.
- Chandi Devi Temple, Neel Parvat, Haridwar 
- Chandi Mandir, Chandigarh. The city of Chandigarh (lit. "fort of Chandi") derives its name from this temple.
- Chandi Mata Mandir Machail, Kishtwar,J&K Sphire valley Paddar
- Chandi Mata Mandir Chinnot, Badherwah,J&K
- Anandavalli Temple, Panchetti, Gummudipoondi, Chennai - The Durga Sapthasathi yantra has been installed by Sage Agastya in this temple.
- Hedavde Mahalaxmi Mata, Maharashtra
- Chandika Devi Mandir, Malgund, (Ratnagiri) (Maharashtra) *Short drive from the famous Ganpatipule Mandir.
In folklore of Bengal 
Chandi is one of the most popular folk deities in Bengal, and a number of poems and literary compositions in Bengali called Chandi Mangala Kavyas were written from 13th century to early 19th century. These had the effect of merging the local folk and tribal goddesses with mainstream Hinduism. The Mangal kavyas often associate Chandi with goddess Kali or Kalika. and recognize her as a consort of Shiva and mother of Ganesha and Kartikeya, which are characteristics of goddesses like Parvati and Durga. The concept of Chandi as the supreme Goddess also underwent a change. The worship of the goddess became heterogeneous in nature.
Chandi is associated with good fortune as well as disaster. Her auspivcious forms like Mangal Chandi, Sankat Mangal Chandi, Rana Chandi bestow joy, riches, children, good hunting and victory in battles while other forms like Olai Chandi cure diseases like cholera, plague and cattle diseases.
These are almost all village and tribal Goddesses with the name of the village or tribe being added on to the name Chandi. The most important of these Goddesses is Mangol Chandi who is worshipped in the entire state and also in Assam. Here the word "Mangol" means auspicious or benign.
- Coburn, Thomas B., Devī Māhātmya. p. 95
- Coburn, Thomas B., Devī Māhātmya.
- Mookerjee, Ajit, Kali, The Feminine Force, p 49
- Wilkins p.255-7
- Wilkins p.260
- Sankaranarayanan. S., Devi Mahatmyam, P 148.
- Chandi Devi Haridwar.
- McDaniel(2004) p.21
- McDaniel(2004) pp. 149-150
- McDaniel(2002) pp. 9-11
- Manna, Sibendu, Mother Goddess, Chaṇḍī, pp. 100-110
- Coburn, Thomas B., "Devī Māhātmya, The Crystallization of the Goddess Tradition", South Asia Books, 2002. (ISBN 81-208-0557-7)
- Manna, Sibendu, Mother Goddess, Chaṇḍī, Punthi Pustak, Calcutta, India, 1993. (ISBN 81-85094-60-8)
- Mookerjee, Ajit, Kali, The Feminine Force, Destiny Books, Rochester, Vermont, 1988, (ISBN 0-89281-212-5)
- Sankaranarayanan, S., Glory of the Divine Mother (Devī Māhātmyam), Nesma Books, India, 2001. (ISBN 81-87936-00-2)
- McDaniel, June, Offering Flowers, Feeding Skulls: Popular Goddess Worship in West , Published 2004, Oxford University Press - US, 368 pages, ISBN 0-19-516790-2
- McDaniel, June, Making Virtuous Daughters and Wives: An Introduction to Women's Brata Rituals in Benegal Folk Religion, Published 2002, SUNY Press, 144 pages, ISBN 0-7914-5565-3
- Wilkins, William Joseph, Hindu Mythology, Vedic and Puranic, Published 2004, Kessinger Publishing, 428 pages, ISBN 0-7661-8881-7 (First edition: Published 1882; Thacker, Spink & co.)