The demons Shumbha & Nishumbha could only be killed by a female child of Parvati. Hence, as advised by Brahma, Shiva used his magic to turn Parvati's skin black. However, the word "Kali" can also mean "death", so Parvati was teased. Parvati was agitated by this teasing, so she performed severe penance to Brahma so as to get her fair...