One interesting idea could be a crossover of the Ghost Rider's powers with Naruto's ninja abilities. For example, Naruto might gain the ability to use the Ghost Rider's chain attacks in his combat style. It could also explore how the two different worlds' moral and ethical concepts interact when these two characters' stories merge.
Well, in 'ghost rider naruto fanfiction', perhaps a cool concept is the Ghost Rider's hellfire being incorporated into Naruto's jutsu. Imagine Naruto's Rasengan with a touch of hellfire, making it an even more powerful and fearsome attack. Also, the story could deal with the idea of Naruto facing inner demons similar to how the Ghost Rider battles his own internal darkness.
Perhaps in this fanfiction, there could be a scenario where Naruto has to team up with some of his friends to take on Ghost Rider. They would have to figure out Ghost Rider's weaknesses, which could be a mix of things from both the Naruto universe and what we know about Ghost Rider. And along the way, they might learn some new things about their own powers too.
One idea could be that Naruto somehow inherits the Ghost Rider bloodline. He could then use the powers of the Ghost Rider in his battles in the Naruto world. For example, his Rasengan might be infused with the hellfire of the Ghost Rider, making it an even more powerful attack.
A plot could involve a magical accident that fuses Naruto and Ghost Rider's essences. This new being has a strange allure and power. In the Naruto universe, female characters start to gather around this new entity. There could be a lot of drama as the harem members come from different ninja clans and have different motives. Some might be in it for the power, some for true love, and they all have to deal with the challenges that come with this new and powerful being in their midst.
An interesting OC could be a street artist. They have a unique connection to the spirit world through their art. One day, while creating a mural inspired by the Ghost Rider, they are possessed by the spirit and become a new kind of Ghost Rider, using their art to fight evil.
Another concept is that Naruto is possessed by a spirit similar to the Ghost Rider. His friends initially fear him, but he has to prove that he can use this new power for good. He might have to learn how to use the power without being consumed by the rage and darkness that often comes with it.
One idea could be that Naruto gains the power of a Kamen Rider. He could use the Rider's abilities in his battles in the ninja world. For example, using the Rider's speed to outmaneuver his opponents during a fight against Akatsuki members.
One idea could be a crossover where Ghost Rider teams up with the Young Justice team to fight a powerful demonic threat that neither could handle alone. Maybe they have to enter the underworld to stop a demon lord from opening a portal to Earth. Another idea is a story where a member of Young Justice is somehow cursed and starts to transform into a Ghost Rider - like figure, and they have to learn to control this new power while still being part of the team.
One idea could be Naruto using his dragon to quickly travel across the ninja world for missions. His dragon could also have unique abilities, like breathing a special type of chakra-infused fire that can counteract certain jutsu.
One idea could be a crossover with Doctor Strange. Ghost Rider's hellish powers could clash or collaborate with Strange's magic in the fight against some interdimensional threats. For example, they might have to deal with demons that are breaking through from different realms.
A possible plot is that the Ghost Rider's hellfire has an unexpected effect on the vampires in Twilight. Since vampires are undead, the hellfire might either have no effect, or it could be the one thing that can truly destroy them. This could lead to a race between the vampires and the werewolves to either use or stop the Ghost Rider. Also, the Ghost Rider could form an alliance with the werewolves as they are more in tune with the natural order which the Ghost Rider also represents in a way.