Some fanfics take a more gradual approach. For example, in 'The Blending of Worlds', there are small rifts that start to appear between the two worlds. As time passes, these rifts grow and elements from each world start seeping into the other. Characters from both Naruto and Rias Bishop's universes are initially confused but then start to adapt and learn from each other.
Well, in a popular one called 'Naruto's New Realm', Naruto discovers a portal that leads to Rias's world. As he steps through, the two worlds begin to merge in a way that combines the ninja techniques with the demonic powers of Rias's realm. It's really cool to see how the two different power systems interact and how the characters from both sides deal with the new situation.
The merge can also happen on a more conceptual level. For example, the idea of friendship and teamwork, which are important in both series, could be the connection. Naruto's belief in his friends and the Digidestined's bond with their Digimon could be seen as similar. This similarity could be the starting point for the two worlds to interact in fanfiction. Writers might have Naruto and the Digidestined team up to fight a common enemy that threatens both the Digital World and the ninja world. They would combine their unique powers and skills to achieve victory.
Typically, they use some sort of magical or dimensional rift to merge the two worlds. For example, Naruto could be sucked into a portal that leads him to the High School DxD universe. Or, it could be a more complex plot device like a powerful villain trying to combine the two worlds for their own gain.
One great Naruto and Rias Bishop fanfiction is 'The Unlikely Alliance'. It combines the unique elements of the Naruto universe with the supernatural aspects of Rias's world in an exciting way. The story has well - developed characters and a captivating plot that keeps you hooked from start to finish.
In a Naruto and Batman crossover fanfiction, their worlds could merge in a few ways. One way could be through a portal. Maybe some sort of evil magic or advanced technology creates a portal between Konoha and Gotham. This would bring Naruto and his friends into Batman's world, or vice versa. Another possibility is that a powerful villain has the ability to manipulate space - time and decides to bring the two worlds together for his own evil purposes.
The worlds could merge through a mysterious portal. This portal could be created by some powerful jutsu in Naruto's world that goes wrong or by an experiment in Build's world. Once the worlds start to merge, the characters would be in for a shock. The ninjas in Naruto's world would see the advanced technology of Build's world, and the people in Build's world would be amazed by the use of chakra.
One way their worlds could merge is through a shared mystery. Maybe there's a strange case in the Naruto world that requires Sherlock's deductive skills. For example, a series of disappearances in Konoha that seem to have no pattern. Sherlock, using his keen observation, could notice small details that the ninja miss. Naruto, on the other hand, with his knowledge of the ninja world and its secrets, could provide context that Sherlock needs to solve the mystery. Their different abilities would complement each other, leading to an interesting crossover story.
In fanfiction, the merge could happen because of a powerful jutsu gone wrong. This jutsu could distort space - time and connect the two universes. In the merged world, the Gundam pilots would have to deal with the threat of ninja attacks. They could use their Gundam building skills to create mechas that are better equipped to handle ninja abilities like genjutsu. Meanwhile, the Naruto characters would be fascinated by the Gundam battles and might try to participate using their own combat skills.
In a fanfic, the merging could also be due to a common threat. Suppose there is a dark force that wants to conquer both the ninja world and the vampire world. To fight this threat, Naruto and Moka's worlds start to merge gradually. This would result in unique alliances. For example, ninja and vampires might have to work together, with Naruto and Moka leading the way. They would need to find a way to combine their different fighting styles and powers, like Naruto's shadow clones and Moka's blood-based attacks.
Their worlds could merge through a magical portal. Maybe a powerful jutsu in Naruto's world accidentally creates a rift that connects to Bayonetta's dimension. This would allow characters from both sides to interact.
Well, one way could be through some sort of powerful magic or ancient artifact. Maybe there's a device that can create portals between the Naruto and One Piece worlds. Since Naruto has the Rinnegan which has powerful abilities like space - time manipulation, it could be involved in opening the gateway. And in the One Piece world, there might be some devil fruits that can interact with the Naruto powers to stabilize the connection between the two worlds.