Yorlngu is a deity in Alradjadu. Although he isn't exactly equivalent to Kali, he certainly takes a similar role in the religion.
I don't think Shakti has a purpose. I'd say she and Kali are the active and creative aspects of Brahman's embodiment in Purusha respectivelyKali is the highest form of the formless Brahman.
The purpose of Prakriti, Shakti, is to know Purusha, Shiva.
Shakti is my activity only.
I rather think that's an error of anthropomorphic assumption.
God's knowledge is not limited nor determined nor dependent — at least, not God as I understand the term.