There is a Kali Temple in South India where non-Indians are taken on tour as a "test."
They are shown the figure of Kali Ma, with all of the "horrific" aspects in full view. If they show fear rather than devotion, it is a sign that they have "evil" inside of them. Those who show pure devotion are clean and clear, since Kali only attacks EVIL and not purity or goodness. The skulls hanging around Her belt indicate the egos She has slain.
Another of Kali’s aspects is that She strikes like a lightning bolt, with life changing completely overnight. She only destroys that which was not built upon a proper firm foundation so the healing and re-construction can begin. (The Tower in the Tarot deck depicts the same concept.)
Mantra: Om Shri MahaKali Namah
Excerpt from: "Navaratri: Nine Nights of Divine Mother" available at www.VishwaGifts.com