Rhaenyra is the key character in this fanfic idea. There could be a new character, perhaps a foreign diplomat who has a hidden agenda and decides to gag Rhaenyra to stop her from interfering in their plans. Her dragon, if dragons are part of the story, could also be a character in a way. It could sense that something is wrong with Rhaenyra and try to find her. And then there are the common people in the story. They might witness her being gagged and start rumors or even try to help her depending on their loyalty to her.
Obviously, Rhaenyra herself would be the central character. Then there could be her captors or those who gag her. If it's a political story, her rivals for the throne like Alicent or her supporters could be involved. Her loyal guards or servants might also play a role. They could be trying to rescue her or help her communicate while she is gagged.
In a 'rhaenyra gagged fanfic', Rhaenyra is the main character of course. There could be mysterious figures from the shadows, like assassins or spies who gag her for their own purposes. Her family members might also be involved. Her father, if still alive in the story, could be trying to find her. And her children, if she has any in the fanfic's timeline, would be worried about her and could be part of the story trying to free her.
Perhaps in a 'rhaenyra gagged fanfic', the plot could revolve around a political intrigue. Rhaenyra is gagged by those who oppose her claim to the throne. This forces her to find alternative ways to communicate with her allies. She could use gestures, or write secret messages. It could also show her inner strength as she endures this difficult situation and still manages to fight for her rightful place.
Don't forget about villains. Cheetah, who has her own connection to the Amazonian lore, could be a great villain in this fanfic. She could be working with some Gotham villains to create chaos in both Themiscyra and Gotham. And perhaps there's a new, original villain created specifically for this fanfic, a power - hungry figure who wants to steal the Amazons' secrets and use them to take over Gotham.
Obviously, Natsu himself would be the central character. His best friend Happy could also be involved, maybe Happy starts to notice some of Natsu's strange dragon - related behaviors first. Gray might also be in the story, perhaps he gets into a fight with Natsu where Natsu's dragon powers accidentally show a bit more than he intended.
Obviously, Miss Martian herself is the central character. Her friends and teammates from the superhero group she belongs to could also be involved. For example, Superboy might play a role as a friend or protector. He could be there to support her during difficult times or help keep her and the baby safe from any threats.
Obviously, Aria herself is the main character. Her family members like her mother and father could be important characters, offering support or having different opinions. Her best friends would also be likely to be involved, providing emotional support or getting into some friendly arguments about how she should handle the pregnancy.
There could be Bella's partner in the relationship she is betraying. This character might be a loving and trusting person, which would make Bella's affair even more complicated and morally wrong.
Well, there could be her best friend who is always there for her during the pregnancy, giving her advice and emotional support. There might also be a mysterious figure, like an old wise woman who has knowledge about pregnancies in special circumstances that Tera Faya's case might be. And of course, there could be a rival of some sort, who might try to use her pregnancy against her in some way.
Igneel could also play a role. Since Igneel was Natsu's adoptive dragon father, he could appear in Natsu's mind during the transformation, guiding him and giving him advice on how to handle his new dragon powers. And there could be other dragons in the story as well. They might be either friendly or hostile towards Natsu depending on their nature.
There could also be new characters introduced. Maybe other magizoologists from different parts of the wizarding world. They could have different approaches and beliefs about magical creatures. Some might be rivals, trying to outdo Harry in the discovery and study of new species, while others could be mentors, guiding him in the complex world of magizoology.
Obviously Ranma herself. Her father Genma could also be a major character as he has to deal with his daughter's new permanent state. Akane could be there too, and their relationship would likely be very different. Instead of the typical boy - girl rivalry, it could turn into a more complex female - female dynamic.