OK, got this from wikipedia.org
It says that Kali grew out of Durga's brows and shares the five characteristics of Durga!!
Slayer of Raktabija
In Kali's most famous myth, Durga and her assistants, Matrikas, wound the demon Raktabija, in various ways and with a variety of weapons, in an attempt to destroy him. They soon find that they have worsened the situation, as for every blood that is spilt from Raktabija the demon reproduces a copy of himself. The battlefield becomes increasingly filled with his duplicates. Durga, in dire need of help, summons Kali to combat the demons. Kali destroys Raktabija by suckling the blood from his body and putting the many Raktabija duplicates in her gaping mouth. Pleased with her victory, Kali then dances on the field of battle, stepping on the corpses of the slain. Her consort Shiva lies among the dead beneath her feet, a representation of Kali commonly seen in iconography, the Daksinakali pose.
[edit] Daksinakali
In her most famous pose as Daksinakali, it is said that Kali, becoming drunk on the blood of her victims on the battlefield, dances with destructive frenzy. In her fury she fails to see the body of her husband Shiva who lies among the corpses on the battlefield. Ultimately the cries of Shiva attract Kali's attention, calming her fury. As a sign of her shame at having disrespected her husband in such a fashion, Kali sticks out her tongue.
One South Indian tradition tells of a dance contest between Shiva and Kali. After defeating the two demons Sumbha and Nisumbha, Kali takes residence in a forest. With fierce companions she terrorizes the surrounding area. One of Shiva's devotees becomes distracted while doing austerities and asks Shiva to rid the forest of the destructive goddess. When Shiva arrives, Kali threatens him, claiming the territory as her own. Shiva challenges her to a dance contest, and defeats her when she is unable to perform the energetic Tandava dance. Although here Kali is defeated, and is forced to control her disruptive habits, we find very few images or other myths depicting her in such manner.
[edit] Maternal Kali
Another myth depicts the infant Shiva calming Kali, instead. In this similar story, Kali again defeated her enemies on the battlefield and began to dance out of control, drunk on the blood of the slain. To calm her down and to protect the stability of the world, Shiva is sent to the battlefield, as an infant, crying aloud. Seeing the child's distress, Kali ceases dancing to take care of the helpless infant. She picks him up, kisses his head, and proceeds to breast feed the infant Shiva. This myth depicts Kali in her benevolent, maternal aspect something that is revered in Hinduism, but not often recognized in the West.
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My feeling is, just like the third story, her maternal instinct will win in the end!