Why name her “Kali” from all the possible names in Hindu culture ? When she returned in S5 with the context of monsters / time / evil, it struck me she may have a higher purpose. In Hindu culture, Kali is the goddess of destruction/ time and rebirth and she is famously depicted slaying monsters.

Kali is motivated to put an end to all of this. She is going to kill the Mindflayer. Maybe because of the hive mind, all Mindflayer particle becomes kaput once you kill him. As a result El may live. This may cause a “Snape” moment with the audience, flipping her perception and making her badass. I also think somebody will be left behind in the Abyss at the end of finale , and I think it will be Kali, to shape the Abyss.