Well, one similarity is the presence of vampires. In both 'A Discovery of Witches' and 'Twilight' fanfiction, vampires often play a major role. They are usually depicted as having special powers and a complex social structure. Another similarity is the theme of forbidden love. Just like in the original works, fanfictions of these two often explore relationships that are not easily accepted by the different species or groups within the story.
Both 'A Discovery of Witches' and 'Twilight' have strong female protagonists. In fanfiction, this often leads to similar themes of female empowerment and the exploration of a woman's role in a world full of supernatural beings. The female characters are often at the center of the story, making decisions that impact not only their own lives but also the lives of those around them. This can be seen in many fanfictions where Diana from 'A Discovery of Witches' and Bella from 'Twilight' are used as models for strong female characters who navigate difficult situations.
The use of magic or special abilities is also a similarity. In 'A Discovery of Witches', there is a rich tapestry of magic, and in 'Twilight', the vampires have their own unique abilities. In fanfiction, these elements are often combined or compared. For instance, a fanfic might explore how the magic in 'A Discovery of Witches' could affect the vampires in 'Twilight'. Also, both stories have a strong sense of a hidden world within our own, and fanfictions tend to expand on that idea, creating more complex and intertwined hidden worlds.