Perhaps in a fanfiction, Ghost Rider and Blackheart are both vying for the love of the same being. This being is an otherworldly entity that holds great power. The love triangle between them could lead to a series of battles and unexpected alliances as they both try to win her over.
First, do your research on the characters. Know Ghost Rider's backstory, his powers, and his motives. The same goes for Blackheart. Then, think about how love can be incorporated. It could be a romantic love or a love for humanity. For example, you could start with Ghost Rider on one of his usual hunts for the damned. Then introduce a character that he starts to feel a strange connection with. As for Blackheart, you can have him notice this new development and try to use it against Ghost Rider. This creates conflict and a starting point for your story.
A great Ghost Rider x Blackheart fanfiction often has a deep exploration of their complex relationship. It should show the conflict between Ghost Rider's sense of justice and Blackheart's malevolence. Good character development is key.
A common theme is the struggle between good and evil. Since Ghost Rider is associated with justice and Blackheart is a villain, the OC often gets caught in this moral battle. Another theme is redemption. The OC may try to redeem Blackheart or vice versa.
Check out Reddit as well. There are subreddits for fanfiction in general and some specific to the Marvel universe. You could post a request for Ghost Rider x Blackheart fanfiction there, and chances are, someone will point you in the right direction. Additionally, following some of the more well - known fanfiction writers on social media platforms might lead you to their works in this pairing.
There's also 'Shadows of Redemption'. In this fanfiction, the OC is a young girl with a pure heart who tries to redeem Blackheart. It shows a different side of Blackheart, and the story is really engaging as it explores how their relationship develops over time. It has some really interesting plot twists too.
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.
In a fanfiction, the Ghost Rider could form an alliance with Batman. Batman would be intrigued by the supernatural element that Ghost Rider brings. They could team up to take on villains who are using magic or other dark forces. Ghost Rider's powers of hellfire and his unearthly strength would be a great asset to the Dark Knight's strategic mind.
In a fanfiction crossover, Ghost Rider could end up in the Mystery Machine by accident. His flaming skull would surely freak out the gang. However, he might need their help to track down a villain who has escaped into the world that Scooby Doo and his friends inhabit. They could combine their skills, with Ghost Rider's supernatural powers and the gang's mystery - solving abilities.
Well, a fanfiction could start with Morrigan Aensland hearing rumors of a being that wields hellfire on Earth, which is of course Ghost Rider. She decides to pay a visit to this strange entity. When they meet, there is an immediate clash of their different natures. Morrigan is used to being in control and using her charm and power to get what she wants, while Ghost Rider is driven by his mission of punishing the guilty. But as the story progresses, they find themselves in a situation where they need to trust each other. Maybe a powerful demon is trying to take over both their territories, and only by combining their powers can they stop it.
One idea could be that Harry Potter, with his magical abilities, meets Ghost Rider in a parallel dimension. Their initial encounter is filled with mistrust as they come from such different worlds. But as they are forced to work together to face a common enemy, they start to understand each other more deeply and a yaoi - themed relationship could develop from there, with shared moments of vulnerability and mutual admiration.