Naruto's ability to sense chakra could be used to detect hidden enemies in the Kamen Rider Drive world. In that world, there might be villains who can cloak themselves using technology. But Naruto's chakra - sensing ability would cut through that and allow him and Drive to be one step ahead in battles. And Drive could use his gadgets to then counter - attack these enemies.
In a more complex way, they could be brought together by a common enemy. For instance, an evil force that wants to steal the power of both chakra and the magic in the Kamen Rider world. They would then need to communicate and strategize to fight this enemy. This would involve Naruto explaining his ninja world concepts like jutsu and clans, while Kamen Rider Wizard shares his knowledge about the Phantoms and magic rings.
Ruby, with her eagerness to grow as a fighter, would study the Kamen Rider's fighting styles and abilities in the fanfiction. She'd be inspired to incorporate some of those moves into her own combat repertoire. Weiss, being the strategic one, would look at how Kamen Rider approaches different situations in the fanfiction and apply those concepts to her own planning. Blake would see the Kamen Rider's fight against darkness as similar to her own fight against the Grimm. She might draw strength from the Kamen Rider's unwavering determination. Yang, always up for a challenge, would be excited by the physical feats that Kamen Rider performs in the fanfiction and strive to match that level of power.
Another interesting aspect of Kamen Rider Dark Drive fanfiction is the exploration of different timelines. Writers can play with the idea of alternate realities, where the events of the series unfold differently. This could lead to unique storylines and character developments that we don't see in the original show.
In a High School DxD fanfiction with Naruto and Ghost Rider, their powers could interact in various ways. Naruto's Rasengan, for example, could be combined with Ghost Rider's chain attacks. Naruto's ability to sense danger through his chakra might also be enhanced by Ghost Rider's supernatural senses. They would both be out of place in the High School DxD setting at first, but their powers would quickly make them forces to be reckoned with.
One common theme is power - ups. Writers often come up with new forms for Kamen Rider Drive, which is really exciting for fans who love to see their favorite hero in different looks. Another theme is alternate universes, like a world where the bad guys won at the start.
Love and relationships are another theme. This could be between the main characters, or it could be about the relationships that develop during their battles and adventures. For instance, a fanfic might explore a romantic relationship between a Kamen Rider and a civilian who gets involved in their fight against evil.
The Powerpuff Girls have powers like super strength, flight, and energy projection. Ghost Rider has his chain, hellfire, and the Penance Stare. If they were in a fight together, the Powerpuff Girls could use their flight to quickly move around and avoid Ghost Rider's attacks. At the same time, Ghost Rider's hellfire might be able to counter the Powerpuff Girls' energy blasts. For example, Blossom's ice - breath power could be nullified by Ghost Rider's intense hellfire.
The characters would likely start off with some level of mistrust. For instance, the Avengers might be suspicious of Build's powers and his motives at first. However, as they face threats together, they would start to respect each other. Iron Man and Build could bond over their love for technology and inventing new gadgets. Captain America might be initially skeptical but would come to admire Build's courage in battle.
The shinobi in Naruto's village would likely be divided. Some would support Naruto's decision wholeheartedly, believing that any unknown power like the Kamen Rider's is dangerous. Others might be more skeptical, especially those who are more open - minded or have interacted with the Kamen Rider. As for the Kamen Rider himself, he would probably be angry and confused at first, but then determined to prove his worth and return.
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.