Another interesting idea is a time - travel based fanfic. The Thirteenth Doctor could accidentally go back in time to a point in Earth's history where she has to solve a mystery that is somehow connected to a future threat she has faced. This would involve her using her wits and knowledge of both past and future to save the day.
One interesting thirteenth doctor fanfiction could be about her adventures in an alternate universe. In this story, she might encounter versions of her old companions in very different circumstances.
Well, in a Thirteenth Doctor OC fanfic, it's important to capture the essence of the Thirteenth Doctor's character. She's energetic, curious, and always ready for an adventure. Your OC could be someone who gets caught up in one of her adventures by accident. For example, they could be a scientist working on a project that the Doctor is also interested in. This could lead to a great story of discovery and teamwork.
One idea could be that Doctor Strange discovers he is pregnant due to some strange magical experiment gone wrong. His powers start to fluctuate in unexpected ways as his body adjusts to the pregnancy. He has to deal with the reactions of his fellow sorcerers, some of whom are shocked and others who try to help him manage his new condition while still protecting the world from magical threats.
One idea could be a time - traveling adventure where the Doctor and Captain Jack team up to stop an alien threat that is disrupting the space - time continuum. They could visit different historical periods and use their unique skills to outwit the enemy.
In a Thirteenth Doctor OC fanfic, pacing is crucial. You don't want to rush the relationship between your OC and the Doctor. Start with small encounters, like the OC seeing the TARDIS for the first time and being curious. Then, as the story progresses, build up to more significant events, such as them traveling together through time and space. Also, pay attention to the dialogue. It should feel natural and reflect the personalities of both characters.
Yasmin Khan would be a great character to include. She was one of the Doctor's companions and her relationship with the Thirteenth Doctor was full of friendship and adventure. Her skills and her growth throughout her time with the Doctor can add depth to the fanfic.
One idea could be that Rose returns during the 12th Doctor's time and has to adjust to his new personality. Maybe she teams up with Bill to help the Doctor solve a mystery on a strange planet. They could discover an ancient civilization that has a connection to Rose's past adventures.
Well, in '1984 fanfic', one interesting idea could be exploring different endings. Maybe the main character manages to overthrow the totalitarian regime in a way not shown in the original. Another could be delving deeper into the relationships between characters that were only hinted at in '1984'. For example, the relationship between Winston and Julia could be explored further, like what if they had a chance to start a real family in a post - Big Brother world.
One interesting idea could be exploring the Doctor's internal conflict during the regeneration process. He might be grappling with memories of his past selves and the adventures he had. Another could be how his companions react to the sudden change. They may be in shock or try to help him through the difficult transition.
One idea could be to create an OC who is a time - traveling medic. They could cross paths with the Doctor during the 'day of the doctor' and use their unique medical skills to help in a crisis. Maybe they have a device that can heal wounds in a different way than the Doctor's sonic screwdriver.