So I recently read an excellently written AU that left me with a bad taste in my mouth. Not because it took a loved character down a darker path, aligning her with the villain instead of the hero (that is what AU is for) and I spent some time pondering why this fic didn't work for me.
What I realized was that the best AUs keep the characters themselves even as they make different choices. At the end of this fic, the character in question didn't feel like herself. Because of the parameters of the AUs, one relationship she had in canon (a pretty important one, too) doesn't exist and there isn't a good replacement for that relationship OR ghosts of that relationship in a different form.
Thus, by the end of the fanfic, I had no emotional connection to the characters and felt like they were paper dolls with familiar names.
What I realized was that the best AUs keep the characters themselves even as they make different choices. At the end of this fic, the character in question didn't feel like herself. Because of the parameters of the AUs, one relationship she had in canon (a pretty important one, too) doesn't exist and there isn't a good replacement for that relationship OR ghosts of that relationship in a different form.
Thus, by the end of the fanfic, I had no emotional connection to the characters and felt like they were paper dolls with familiar names.