Baba Yaga

One of the Wyches of <order name>. Was active in the human empire. word of her potentially taking a contract for The King's life is what drove him to lychdom. her deadly reputation is that strong.
Before/during/after the fall of humanity, she retired. buried her staff and spellbook (beneath concrete). She's kept to a normal life (probably some kind of hermit). not getting involved in anything.
There should be an interesting questline to get her back in. She'll crack the concrete and dig up her wands/staff like John Wick.
She has killed hundreds or more people. She's not a good person. but she's skilled. and she's cool.
hook ideas:
* she has a descendent who is in trouble (probably estranged) (EASY way to tie her into any campaign). * she needs to be employed to assassinate someone (or maybe some undead part of the human empire).