The exploration of the High School DxD lore is also a common theme. Writers often expand on the existing lore, like the different ranks of devils, the history of the three factions (devils, angels, and fallen angels), and how magic works. They might introduce new elements to the lore that fit well with the original world - building, which makes the fanfiction more interesting for readers who are already familiar with the original series.
One common theme is power growth. Many fanfictions focus on the main character getting stronger in the High School DxD universe, whether it's through new powers or better control of existing ones.
Another theme is relationships. This can include romantic relationships between the self - inserted character and the original characters like Rias or Akeno. It also involves friendships and rivalries that develop as the story progresses. In a lot of these fanfictions, the relationships are complex and add depth to the overall story. For example, some explore how the self - inserted character navigates the different social hierarchies in the school, which is full of devils, angels, and other supernatural beings.
Transformation is also a popular theme. Given ACNologia's nature, fanfictions may involve him undergoing some sort of transformation, either physically or in his personality. This can be due to the influence of the High School DxD environment or his interactions with the characters. And this transformation can then drive the plot forward in interesting ways.
Friendship is also a big theme. Characters from both universes form new friendships and alliances. For example, Naruto's idea of comradeship might influence the characters in High School DxD and vice versa. They learn from each other's values and work together to face challenges, whether it's school - related in the High School DxD setting or something more global like in Naruto's world.
One common theme is the exploration of relationships. Given the nature of the original series, many fanfictions focus on the romantic or friendship relationships between Uri and other characters.
One common theme is Asia's growth. Since she starts as a rather timid character in the original, fanfictions often focus on her becoming stronger. Another theme is her relationships, like her friendship with the main characters.
One common theme is power growth. In both Naruto and DxD, the characters are constantly striving to become stronger. Fanfictions often combine these two elements, showing how characters from one series adapt to the power - up systems of the other. For example, Naruto characters might learn about the Sacred Gears in DxD.
One common theme is the clash of different worlds. Spiderman's world of superheroics and the supernatural world of High School Dxd collide. Another could be friendship, as Spiderman might form new bonds with the characters in the High School Dxd universe.
A prevalent theme is the adaptation to a new environment. Dean, coming into the High School DxD universe, has to adapt to the different rules, cultures, and power dynamics. There are also themes related to loyalty and betrayal. In many fanfictions, Dean has to figure out who he can trust among the various characters, some of whom might be plotting against him while others are true friends.
One common theme is the clash of different ideologies. Since Alexander Anderson has his own set of beliefs and values, when he enters the High School DxD world, which has its own complex moral and power structures, there is often a conflict. For example, his strict sense of justice might not always align with the more chaotic and self - interested nature of some DxD characters.
One common theme is power. Since the OC is a god, there's often a focus on their extraordinary powers and how they use them in the high school setting of DxD.
One common theme is power. Since both Naruto and High School DxD have complex power systems, fanfictions often explore how the characters' powers interact. Another is friendship, as in how Naruto's idea of friendship might influence the relationships in High School DxD. And of course, there's the theme of adventure, with Naruto getting involved in the wild adventures that usually happen in High School DxD.