One interesting plot could be that they discover a hidden Time Lord society and have to navigate its complex politics and rules. Another could be that they are forced to work together to prevent a time paradox that threatens to erase both of their existences.
Maybe in a fanfiction, the Doctor and the other Time Lord have to race against time to stop an ancient evil that was awakened by their accidental encounter. Or they could find themselves in a battle of wits to determine who has the better understanding of time and its manipulation.
One interesting plot could be Rose and the 11th Doctor getting into a time - related mystery. Maybe they end up in a time loop and have to figure out how to break it together. Another could be them encountering a new alien species that challenges their understanding of the universe.
Themes in such fanfiction usually include resolving conflicts between different versions of the Doctor and showcasing their growth through this encounter. Elements like shared memories and unique abilities coming into play are also common. Sometimes, it even explores the concept of fate and destiny for the Doctors.
One interesting plot could be that Doctor Proctor discovers a new and rare Pokemon disease. He has to travel to far - off regions in the Pokemon world to find the cure. Along the way, he meets various Pokemon trainers who either help or hinder his journey.
One interesting plot could be that the kiss is a moment of realization for both Clara and the Doctor. It might be the moment when they finally admit their hidden feelings that have been building up throughout their adventures. For example, they could be in a dangerous situation, and the kiss gives them the strength to face the danger together.
Frequently, the fanfiction focuses on the internal struggle of the Doctor dealing with the immense power and responsibility that comes with being Time Lord Victorious. It also explores the impact on his relationships with companions.
One idea could be that they team up to face a new alien threat that is beyond what either of them has faced alone. Maybe an alien that can manipulate time in ways that disrupt the fabric of reality. Another could be a story where the Doctor and the Torchwood team have a clash of ideologies at first regarding how to handle a situation with a lost alien civilization on Earth, but then they learn from each other.
One interesting scenario could be the 11th Doctor and Rose exploring a new and strange planet together. They might encounter unique alien species that test their wits and courage. Another could be a moment of emotional reunion, where the Doctor realizes how much he has missed Rose during his different regenerations.
In these fanfictions, a frequent theme is time - related chaos. Since they are both time - traveling Doctors, they might accidentally disrupt the time - space continuum and have to fix it together. There's also the theme of self - discovery. As they interact, they might learn new things about themselves. For instance, the Tenth Doctor could learn to be more carefree from the Eleventh Doctor, and the Eleventh Doctor could learn about the importance of taking things seriously from the Tenth Doctor. Additionally, the theme of nostalgia can be present. The Tenth Doctor might remember his past adventures, and the Eleventh Doctor could be intrigued by them.
Some fanfictions might focus on the relationship between the Doctor and Clara during this time. They could expand on their interactions and how Clara copes with the Doctor's situation, which is a very engaging aspect. For example, Clara could have her own secret plans to help the Doctor during his stand on Trenzalore.
Well, a key feature could be a distinct personality that sets them apart. Maybe they have a particular mission or goal that drives the story. Also, their appearance and costume design often play a role in making them stand out.