The Snow Queen
I particularly like Andersen's idea of the warping mirror, and I might shamelessly steal the idea and use it in other ways at a later date. There's a lot to be said for the idea of a poisonous presence working its way into the hearts of people and distorting their view of the world (bit like social media, really). Is it a warning against self-absorption or against the dangers of self-hatred? The Snow Queen herself also needs an opportunity to chew the scenery far more than she gets to do in either my version of the story or the original one. She certainly enjoyed her incarnation as Jadis in Lewis' books about Narnia.