Obviously, the 12th Doctor himself is a central character. Then there's Clara, his companion. Their relationship is often explored during the regeneration process, as she might be there to witness it or even have some influence on how it unfolds. Another common character could be the TARDIS. It's an important part of the Doctor's life, and in fanfiction, it might react in unique ways during the regeneration, like the console lights flickering in a special pattern.
The main character would surely be the 10th Doctor himself. His companions, depending on the era, like Rose Tyler or Martha Jones, could also be main characters. They play important roles in how the Doctor adjusts to his new form.
In many fanfictions, the 10th Doctor's emotional journey during regeneration is complex. He not only has to deal with the physical pain of the process but also the emotional turmoil. He may be afraid of what the new version of himself will be like. There are also memories of his past regenerations flooding back, adding to his distress. And his relationships with his companions play a huge role. He might worry about how they'll react to his new form, and whether they'll still be by his side. All these emotions are often explored in great detail in fanfictions.
His companions like Amy Pond and Rory Williams are often involved. They are important as they have been with the 11th Doctor through many adventures and their reactions to his regeneration are crucial parts of the story.
One notable thing is the way these fanfics handle the power dynamics. Sometimes they give the female regeneration unique abilities or challenges. Also, the character development can be quite intense and complex.
These fanfictions often explore new perspectives and challenges for the Doctor. They might focus on how the female regeneration changes the way she interacts with companions and faces enemies.
Well, it could be about many things. Maybe it focuses on the early days of the 10th Doctor's regeneration process, like how he copes with his new body, new personality traits that start to emerge, and his first encounters with old and new enemies. It might also explore the reactions of his companions during this initial phase.
Well, it could lead to all sorts of adventures and challenges for Donna and the Doctor. Maybe they have to find a way to protect the baby in the face of intergalactic threats.
Such fanfiction often explores unconventional and passionate relationships. The lemon aspect might add a more adult and intense flavor to the story involving Donna's character.