Rakteswari

Rakteswari (also Rakteshwari), identified as an aspect of Adi Parashakti, also known as Durga Parameswari, is a principal and popular form of Hindu goddess worshipped mainly in "Parshurama Kshetras". Rakteswari is the iṣṭa-devatā (tutelary deity) of Tulu Nadu.
Worship and festivals.
Rakteswari is Durga Parameswari, the divine mother of universe, worshipped in Hindu temples of India by Shakta Hindus. Her temples, worship and festivals are particularly popular in Indian subcontinent during every Sankramana (or Sankranthi days/ Sun transit days of every month in Hindu calendar). Coconut flowers, Vermilion and whole coconuts are the significant offerings for her worship.
The "beeja-mantra" of Rakteswari, "Om Kleem Ram Rakteswaryai namaha", is recited on Sikharagra (on top of a mountain), near a flowing river, any dense forest, Kadamba trees garden,etc. under the guidance of a competent guru as any "shakta (Shakta Upanishads)" tradition requires.
Deity Rakteswari is often misunderstood as a spirit/demon. "Dakshinachara" sects are dismissive of Rakteswari as a goddess who demands blood sacrifice.She is a fierce deity worshipped in her calm posture in "dakshinachara" path (Right-Hand Path) with "kumkum (Vermilion)" and whole coconut as "bali" (offerings). Speciality of the goddess worship is that it bestows the seeker with a power to extract negative energies (i.e. any blockages in "shat" chakras (centers of energy) of human body causing anxiety, fear, depression, loss of appetite, anger, frustrations, loss of concentration, etc.) from other human beings using certain mudras (internalized energetic practices) especially on "Sankramana" days of every month (refer to table below for exact dates).
Some accomplished Rakteswari worshippers are known for performing spiritual healing (cleansing of the blockages of seven chakras in human body) through mastery of Rakteswari worship. Prescription of beej mantra "AUM" is done (time of recitation could vary based on the specific blockages) as one of the main "satvik" post-healing processes.
Planet Mars and its association with goddess Rakteswari.
In traditional Hindu astrology, Moon, Mars are the chief significators of blood in human body. When Mars is afflicted in any horoscope and it occupies an even sign, then goddess Rakteswari has to be propitiated to get rid of any blood related disorders. As per some local beliefs, contagious diseases like Smallpox and menstrual bleeding disorders(Mars represents private parts of body too) can be cured by worshipping Rakteswari 
The Vamamarga worship( Left-Hand Path or alternate path which uses wine, meat, blood, animal sacrifices, etc.) of Rakteswari is not ruled out in folklore genre. The Folk performances mandate music, folk dance, recital and other elaborate vesha (costumes ) as outlined in Dravidian Tulu Oral folk literature, Cow ghee lamp and "Kumkum" (Vermilion) are offered to appease Rakteswari in typical household worship, like any other female deity.
Temple.
The regions of Konkan, coastal Karnataka and Kerala, considered as Parashurama Kshetra, have numerous temples dedicated to Rakteswari. Worship of Rakteswari by Brahmins and many other various Hindus in m"ulasthana" is famous in South Canara.
Rakteshwari, in "Dakshinachara (Right-Hand Path)" tradition, is depicted as "srichakravasini" (peaceful and soothing deity as a resident of the tip of Sri Chakra) and worshipped as Durga Parameswari by Durga sukta and Śrī Sūkta.
Iconography.
Sword, one of the divine weapons of Adi Parashakti, which represents elimination of Discrimination according to "Devi Mahatyam", is a symbolic form of goddess Rakteswari. The tip of Sri Chakra is an iconic form of the supreme goddess, Durga Parameswari.