Friendship is also a big theme. The OC might start as a stranger to Luna but then they develop a deep friendship through shared experiences, like helping each other out in difficult situations or just having common interests in the world of duels.
Love is also a prevalent theme. The fanfictions often explore the romantic aspect of their relationship. They might go through the typical stages of a budding romance like the first blush of attraction, misunderstandings, and finally coming together. This can be seen in fanfictions where they have to overcome obstacles in their relationship like differences in their social status within the Yugioh 5ds world or misunderstandings about each other's intentions.
One common theme could be friendship. Since the 'yugioh' series often emphasizes the bonds between characters, in 'luna lemon' fanfiction, it might be about Luna's friendships and how they develop. Another could be adventure, as the characters in 'yugioh 5ds' are often on exciting adventures.
One popular place to find Yugioh 5ds Luna x OC fanfiction is Archive of Our Own (AO3). There are many stories there that explore different relationships between Luna and original characters. Just search for 'Yugioh 5ds Luna x OC' on the site.
Growth is another theme. Both Jack and Yusei are characters who have grown throughout the series, and fanfictions often continue this growth arc, showing how their relationship affects their individual development, like how they learn from each other's strengths and weaknesses.
Love and loyalty is also a very common theme. Many fanfictions show how Jack and Carly develop feelings for each other and how they stay loyal through various challenges in the 5ds world. For example, in some stories, they face difficult duels or threats from other characters, but their love endures.
Another theme is the concept of the outsider. Since vampires are not the norm in the 5ds universe, they are often seen as outsiders. The fanfictions explore how they try to fit in or change the existing order. They may face discrimination from other characters at first but then prove their worth through their dueling skills.
One possible title could be 'Akiza and the Mysterious OC: A Yugioh 5ds Tale'.
The plot could be that the OC is a new duelist in the city. Akiza notices the OC's unique dueling style which is different from what she has seen before. They start as rivals but gradually develop a friendship as they learn from each other's dueling strategies.
One of the main themes is love. It could be a romantic love or a deep platonic bond that forms between Marik and the oc. Also, power dynamics can be a theme. The oc might have a certain power or skill that changes the power balance between them and Marik. Another common theme is the struggle against inner demons. Marik has his own inner demons, and the oc may play a role in helping him face them.
One common theme is self - discovery. The oc often discovers new things about themselves through their relationship with Yami. Another theme is power and its use. They might learn how to use their own powers or help Yami with his. And of course, friendship and loyalty are big themes too. They support each other through difficult times.