This is quite possibly the worst series I have ever read. It is a classic case of the cardinal rule of writing being broken - show, don't tell. This is apparent by the appearance of Original Characters being introduced and then gaining more and more book space as the series goes. This can work well, as is the case with the Kingdom Hearts video game series despite bizzare storytelling. In this case, however, the author claims authorship for all Disney villain origins and does it in the most irritating way possible, with the Original Characters speaking at great length, in disjointed and unintelligible dialogue mind you, about the respective movies in question through their point of view. It is extremely lazy writing for the writer to allow the characters to "speak for themselves" in that the dialogue goes in odd tangents, but the author does not take charge of the story by planning nor guiding it.
There are entire chapters dedicated to the OCs analyzing movie scenes and retconning it as something they're responsible for. Additionally, the author doesn't even appear to understand her own characters' motivation as characters will flip-flop multiple times within the same chapter as to decisions they have stated they will make, then ultimately decide against because "it's gross," despite already knowing everything involved. Additional characters assault us as meaningless additions to the story in a shameless attempt by the author to plug her own "creativity." Mrs. Tiddlebottom. Mrs. Pickle. Need I say more?
To be honest, I do get a good deal of satisfaction out of reading these stories for the sheer absurdity that is contained within. Every story seems to push this strange fascination the author has with sisters and their relationships with each other. It reads as a childish form of wish fulfilment the author has into what it might be like to have sisters and what one might do for them. Again, sounds good on paper, but clearly the author does not have sisters as every interaction is forced, and the dialogue at no point resembles any that siblings might have. At multiple times throughout the series, the author describes in great detail how nice it must be for sisters to be able to read each others minds, and the OCs are constantly and irritatingly interrupting actual Disney characters with ham-fisted "Woops, I just read your mind, did you forget I could do that? Because I can. Hey! I can read your mind! Did I just tell you that, because I'm going to point it out at every possible moment!"
Every entry in this series becomes more and more disjointed and impossible to follow without previous exposure to previous novels, which is more lazy writing, and I cannot fathom why Disney Press would ever allow someone to destroy their creations with such vapid and myopic works as Serena Valentino's. If you want quality Juvenile Fiction that anyone can enjoy, try the Twisted Tales series by Disney Press.