Kali is the highest form of the Supreme. Kali's name has two meanings; the first meaning is "dark" which means she represents the Void. The second meaning is "Time" which is the Destroyer of Everything. When Asur and Dev were having samudra madan than halahal came out, shani was who was ready to drink that poison halahal, than Lord Shiva stopped him and said i will drink, when he drank that he was about to die, but mahakali came to save him. and he was saved. If there is death then there is also life.