It is an old story. Perhaps the oldest story there is. In the dark woods, there is a witch called Baba Yaga. Sometimes she is a mother. Sometimes she is a daughter. Sometimes she is cruel and sometimes, kind. But always, Baba Yaga is cunning. And there is always a price to pay for dealing with her, if you are brave enough - or desperate enough - to seek her out.
It is said that Baba Yaga waits for travellers in her house atop its gnarled chicken legs, behind a fence made of human bones. If you are brave enough to pass through the fence and enter the house you will see her stretched out across the interior, looming over her stove, or reaching out from one corner to another. Or, if you are in the woods late at night, you might see her flying overhead in her mortar and pestle and the hear the thunderous tramp of the chicken-legged house as it pursues its mistress.
Regardless, she is an ugly creature with a long nose and cruel, iron teeth, and her eyes gleam with malice. But despite her inherent malevolence, she does not interfere with others without first being approached - or provoked. If you are foolish enough to seek her, she might well punish you for your effrontery before aiding you, or aid you and then tear you to pieces because it amuses her to do so. And sometimes, very rarely, she helps without harm.
But only when it suits her to do so.
Now, as the world shudders on its axis and new horrors rise, Baba Yaga stirs in her long isolation. The gods have ignored her warnings for long enough, and if they will not ask for her help willingly, she will find a way to force them to do so.