The Cullens themselves are the main characters. There's Carlisle, the patriarch of the family, who as a human now has to use his medical knowledge in a new way. Esme, who might be exploring her newfound humanity with a sense of wonder. And then there are the younger Cullens like Edward, Bella (if she's involved in this particular fanfiction), and the others, each having their own unique experiences and reactions to becoming human.
Nero Wolfe in 'rex stout nero wolfe complete 47 novels' is a very unique detective. He is overweight and prefers to stay in his home most of the time, but his mind is sharp as a tack. He uses his deductive skills to solve various mysteries, often relying on his assistant Archie Goodwin to gather information for him. He has a passion for orchids and a refined taste in food, which are some of his distinct characteristics.
Well, a major concept is the power dynamics. Mobians may have different power levels compared to humans. When a human turns into a mobian, they might gain or lose certain powers. This can lead to all sorts of plot developments, like having to deal with new enemies or allies. And there's the concept of appearance change. How do they look now? Do they like their new look? And how do others react to their new mobian appearance?
A really cool plot could be that they turn into humans and then try to blend into high school as normal students. They have to deal with typical high - school drama like fitting in, making friends, and dealing with bullies, all while hiding their true identities from everyone around them.
Well, perhaps the plot could involve the chipmunks accidentally getting turned into humans due to some wacky experiment gone wrong. Then they have to navigate the human world, like going to school and making new human friends while still retaining some of their chipmunk quirks.
Well, clearly the two main characters are Nick and Judy. In this fanfiction where they turn human, Nick would be a very interesting character. He might be using his street - smart skills in a new human context. And Judy, she would be the moral compass, trying to uphold what's right in this new human world they find themselves in. They are the central figures around which the whole fanfiction story would revolve.
The crystal gems, for sure. Garnet, with her combined wisdom as Ruby and Sapphire, would be a very interesting human. Amethyst, with her wild and carefree nature, would also be a main focus. And Pearl, with her grace and intelligence, would bring a different flavor to the human - turned - crystal - gem story.
I recommend "Wandering Skeleton", a fantasy-mystery fantasy novel. The plot of the protagonist becoming a skeleton after death and being hunted down while wandering is similar to the plot described in the question. I hope you like this fairy's recommendation. Muah ~😗