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.
One interesting idea could be the exploration of the crystal gems' newfound human emotions. For example, how they deal with things like vulnerability and mortality. Another could be their interaction with the human world in a more 'human' way, like going to school or having a regular job.
The characters can vary depending on the specific fanfiction. It might include main characters like Steven, Garnet, Pearl, and Amethyst, or it could introduce new characters created by the author.
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.
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 main characters might be a team of adventurers. One could be an archaeologist who stumbles upon the knowledge of the human - form Infinity Gems. Another could be a martial artist who has some of the Gem's power within him without realizing it, like the Reality Gem. And a young wizard - in - training who is the Time Gem in human form. Together, they face the challenges that come with the Gems.
In a fanfiction where the Gems turn human in 'Steven Universe', they would likely experience a whole new set of emotions and physical limitations. For example, they would no longer have their gem - based powers. Pearl might struggle with the concept of being mortal and having to learn skills like cooking and cleaning from scratch. Amethyst could find the human form both exciting and frustrating as she'd have to deal with things like getting tired easily. Garnet might have an interesting time adjusting as she's used to being a fusion.
Firestar would be an obvious choice. As a very strong and respected cat in the warrior cats series, as a human he could be a natural leader, perhaps leading the group of cat - turned - humans in their new human lives. Another could be Graystripe. His loyalty and friendship would translate well into a human character, being a reliable friend and ally to the others.
Definitely. There's a story called 'Crystal Gems: New Beginnings' that I really liked. It shows the Crystal Gems in a different light, facing new challenges and forming new relationships. And on Tumblr, there are some short but engaging fanfictions that focus on specific aspects of the Crystal Gems, like their daily lives or their interactions with other characters in the show.
Typically, Harry Potter himself is a main character. He is likely to be involved with the crystal in some way, whether it's trying to discover its powers or using it to fight against evil.
I'm not sure as there's not enough information given. It could be original characters created by the fanfiction writer, or it could be characters from an existing franchise that the fanfiction is based on.