Often, his relationship with his bandmates can be a theme. How they interact during rehearsals, on tour, and in the studio. Also, his influence on the music scene might be explored in fanfiction. Some stories could be set in an alternate reality where Jack White's music has an even greater impact on popular culture than it already does, and how that changes the music industry and the lives of the people in the story.
A prevalent theme is also their growth as individuals. Fanfictions may show how they develop their skills and personalities over time. For example, they might start as inexperienced musicians and grow into superstars. And of course, the theme of adventure can be found in some, where they embark on exciting trips or experiences together.
Friendship is a very common theme. Writers often explore how Kim and Jack support and care for each other. Another theme is adventure, as they are sent on various quests or missions in many fanfictions.
Survival is a common theme. Given their rough and dangerous worlds, they often have to fight to stay alive.
Overcoming challenges is also a big theme. Many fanfictions will create some sort of obstacle or problem that Mark and Jack have to face together. It could be anything from a villain in a fictional world to dealing with some sort of personal crisis. By working together, they grow as characters. For example, in some stories, they might have to overcome a communication barrier between them which makes for an interesting read as you see how they learn to understand each other better.
One common theme is romance. Fans often write about Jack Harlow falling in love with an ordinary person or another celebrity. It's a way to create a fantasy relationship with him.
One common theme is the hero's journey. Jack often has to face challenges and grow as a character, much like in traditional hero stories. Another theme is magic and the supernatural. Since it's related to Potter, there's usually a lot of magic involved.
Another theme is his relationship with the Winchester brothers. In a lot of 'jack supernatural fanfiction', it shows how Jack is mentored by Sam and Dean, or how he sometimes challenges their beliefs. For example, in some stories, Jack might question their methods of hunting and suggest different ways. It's really interesting to see how their dynamic plays out in different fan - created scenarios. And it often explores how Jack fits into the family dynamic of the Winchesters, whether as a son - like figure or something more complex.
One common theme is adventure. Since they are both associated with the pirate world, fanfictions often include exciting sea voyages and battles. Another theme is love, of course. Their complex relationship is explored in many ways, from the initial attraction to deeper emotional bonds.
Love is a theme that sometimes pops up. Some fanfictions might explore the idea of Jack and Kim having romantic feelings for each other, although not all of them do. It adds an interesting layer to their relationship and the story as a whole.
Redemption is also a theme that pops up in Jack and Kate fanfiction. Maybe one of them has made mistakes in the past and they are on a journey to make up for it. Family is another theme that can be seen. It could be about building a family together or dealing with family issues from their past. And of course, friendship is there, as their relationship often has elements of deep friendship that can be further explored in fanfiction.