Another theme could be adventure. Since Yu - Gi - Oh! has elements of adventure and dueling, the OC and Mokuba might go on adventures together, whether it's exploring a new dueling tournament or uncovering some mystery in the Yu - Gi - Oh! world. This theme allows for a lot of action and character development within the fanfiction.
One good kaiba x mokuba fanfiction could be 'The Bond Beyond Brothers'. It focuses on their strong relationship and how they support each other through various challenges in the Yu - Gi - Oh! universe.
You can try fanfiction websites like Archive of Our Own (AO3). It has a large collection of fanfictions, and you can search for 'Mokuba Kaiba x OC' specifically. There are often filters to sort by popularity, rating, etc.
A frequently seen theme is redemption. The OC might be the catalyst for Seto Kaiba's redemption, helping him to overcome his past traumas or his more negative traits. There are also fanfictions where the theme is adventure. The OC and Seto Kaiba embark on some sort of adventure together, whether it's in the world of Duel Monsters or in some other fantastical realm. And sometimes, there are fanfics that focus on the theme of self - discovery. The OC helps Seto Kaiba to discover more about himself, and vice versa.
Archive of Our Own (AO3) is also a great place to look for kaiba x mokuba fanfiction. It has a wide variety of works, and the tagging system makes it easy to filter out exactly what you're looking for. Some stories might be more focused on their relationship development, while others could be adventure - based with their relationship as a backdrop.
One common theme is family bonds. Since they are brothers in the original context, some fanfictions might explore the relationship in a different way, like a deeper emotional connection that could be misconstrued as something more romantic. Another theme could be protection, with Seto being very protective of Mokuba.
One common theme is the overcoming of differences. Kaiba is often portrayed as cold and aloof, while Tea is warm and friendly. Fanfictions usually explore how they bridge this gap. For instance, in many stories, they start off disliking each other but gradually find common ground through shared experiences.
A common theme is the transformation of their rivalry. Instead of just being enemies in dueling, they start to understand and respect each other on a deeper level.
One of the common themes is personal growth. In a lot of 'kaiba x joey fanfiction', both characters grow as individuals because of their interactions with each other. For example, Kaiba might become more in touch with his emotions, while Joey might learn to be more strategic. Also, the theme of trust often comes up. They have to learn to trust each other in various situations, whether it's during a dangerous adventure or just in their day - to - day interactions.
One common theme is loyalty. Noah and Mokuba often show deep loyalty to each other in these fics. For example, in many stories, Noah will go to great lengths to protect Mokuba from harm.
One common theme is power dynamics. Kaiba is often depicted as the more powerful one, and his possessiveness can be related to his need to control. Another theme is loyalty. Joey might question his loyalty to Kaiba due to the possessive behavior.