Vila - Any of a class of Slavic dryads who are exclusively female. They are often vicious and cruel. However, if one succeeds in approaching a Vila properly, she may be inclined to heal, reveal treasure, or teach magical & medicinal arts.
Harry Potter meets the myth. Katniss Everdeen fights like a myth. The use of a familiar myth helps make the magic more plausible because you already have practice in imagining these fantastic gods and creatures.