Crossover interactions. For example, Naruto might interact with Issei from DxD and they could either become friends or rivals. There are also interactions with the different factions in DxD like the devils, angels, and fallen angels. And Naruto's Saiyan nature might make these interactions even more complex and interesting.
A common theme is also adaptation. Naruto has to adapt to the new rules and power levels in the DxD universe with his Saiyan powers. He may have to deal with the fact that his Saiyan strength is different from his ninja skills and find ways to combine them effectively. This can lead to him growing as a character and facing new challenges that he wouldn't have in his original Naruto world.
A common theme is power - up. The Saiyan prince often brings new ways for Naruto or other characters to become stronger. Another theme is friendship. Despite coming from different worlds, they form bonds.
The clash of cultures is also common. The Saiyan's more aggressive and battle - hungry nature compared to the Naruto world's values of friendship and village protection. For instance, a Saiyan might initially not understand the concept of protecting a village but gradually come to appreciate it. And also, the exploration of new power forms that blend Saiyan and Naruto elements like a chakra - infused Super Saiyan form.
The clash of cultures is another theme. The Saiyan way of life, which is very different from the ninja way in Naruto, often leads to interesting storylines. For example, how a Saiyan - like character would adapt to the values of the ninja villages or vice versa. And also, the exploration of the dark side of power. Saiyan powers can be extremely dangerous if not controlled, and many fanfictions explore how characters deal with this dark aspect of their newfound abilities.
One common theme is power - up. Characters from both Naruto and DxD often gain new powers or abilities when combined in fanfiction. Another theme is the exploration of different cultures. Since Naruto has its ninja culture and DxD has its own demon and angel - related cultures, fanfictions often explore how these cultures interact.
Power - up is a common theme. Naruto getting the power of a legendary super saiyan and becoming extremely powerful. Another could be the shock of his friends and foes when he reveals this new power.
One possible plot is that Naruto is transported to the DxD world and discovers he has the latent powers of a Devil Saiyan. He has to learn to control these new powers while also dealing with the complex politics and power struggles in the DxD world. He might form alliances with some of the devil clans or the angels, depending on the situation, all while trying to find a way back to his own world.
The uniqueness also lies in the potential for new story arcs. Since it's a crossover, the writers can take the story in any direction they want. They can create new villains that are a combination of threats from all three universes. For example, a villain who can use both Orochimaru's jutsu and the devious plans of the Highschool DxD antagonists, while also having Saiyan - like strength. This allows for a lot of creativity and makes the fanfiction genre really exciting.
Another theme is the clash of cultures. Naruto comes from a ninja - based culture, and DxD has a very different supernatural culture. Fanfictions often explore how Naruto reacts to the different social norms, values, and power structures in DxD. It can be really interesting to see how he tries to find his place in this new world.
One common theme is the power - up of the characters. Since Naruto characters have their own unique powers and High School DxD has its own system, when combined in fanfiction with a character like Millet, there's often a focus on how they gain new abilities or enhance their existing ones.
Power-ups are a common theme. Since Naruto already has his ninja powers and then enters the DxD world with its own set of powers like Sacred Gears, a lot of fanfics focus on how he combines or enhances these powers. For example, he might learn to use his chakra in new ways because of the DxD environment.