Who could be the main characters in a 'keith turns into a girl' fanfiction besides Keith?

Well, perhaps the story could start with Keith being exposed to a strange energy. This energy alters his DNA, turning him into a girl. As a girl, he finds that he's now treated differently in society. He uses this experience to understand the struggles that girls face. He might also have to adapt to physical changes like different body strength and new ways of expressing emotions.

Obviously, Keith himself in his baby form would be a main character. His friends like Lance, Pidge, Hunk, and Shiro would also be main characters as they are the ones who would most likely be taking care of him or trying to find a cure. Maybe Allura and Coran could also be important characters, helping out with their knowledge of Altean technology or magic that might be related to Keith's transformation.

Well, the plot could involve his friends or comrades having to take care of him as a baby. Maybe they struggle to figure out how to feed him the right things or keep him entertained. For example, they might try different alien foods to see what baby Keith will eat.

Even fictional characters from English literature could be involved. Sherlock Holmes could be brought into the story to help solve any mysteries that might arise due to England's transformation. He could use his deductive skills to figure out the cause and consequences of this strange event.

It could be an old enemy of Keith's, someone from his past who has a vendetta against him. Maybe a former rival from his days in the military academy who has now turned to more devious means.

Obviously, Keith and his mom are the main characters.

There could be his victims. They might not recognize him at first when he turns into a girl and he could use this to get closer to them. Another character could be a mysterious figure who either caused the transformation or is trying to help Jeff reverse it.

Germany would likely be a main character. He has a close relationship with Italy in the original series, and Italy's transformation would surely affect their dynamic. He might be confused at first but then grow to accept and support Italy in this new form. Another could be Romano. As Italy's brother, he would have a very strong reaction to Italy's change. He might be overprotective or even a bit jealous if other countries start to show too much interest in his now - female sibling.

I'm not sure of the exact title, but I once read a fanfic where Keith turns into a girl and it was really interesting. It had a lot of character development for Keith. The story started with the sudden transformation and then went on to show how he coped with things like having to wear different clothes in the Voltron base. His interactions with Lance also changed in a really unique way, as Lance was initially quite flustered by the change but then they developed a deeper bond based on mutual understanding.

His friends from his original life could be main characters. For example, if he has a best friend, that person would play an important role in helping Kuroko adjust to being a girl. Maybe they would offer support and advice, or just be there to listen when Kuroko has a tough time dealing with the changes.