Sri Prathyangira Devi, synonymously referred to as Atharvana Bathrakali and Singhamukha Kali Devi is a Ugram (Fierce) deity devoted to cleansing all ill wishes, evil eyes, black magic and other such impurities from the path and lives of her devotees. Since she is in a Vega manifestation, this makes personal or home worship of her inappropriate for devotees. Therefore the danvantri peedam walajapet gives you the opportunity to partake in this Homam & Pooja Performed monthly on amavasai day.
A homa or fire oblation is made in worship of Pratyangira Devi, the universal Tamil version