One idea could be an OC who is a witch from a long - lost coven that has a unique power related to time manipulation. This OC could accidentally get involved in Buffy's battles when trying to correct a time - related mishap in the supernatural world. Another idea is an OC who is a half - vampire, half - human hybrid, struggling to find their place between the two worlds. They could initially be seen as an enemy by Buffy but later become an ally.
An interesting OC could be a demon hunter from a different dimension. In this fanfiction, the OC comes to Sunnydale because they've heard of Buffy's reputation and want to learn from her. They bring with them their own set of weapons and fighting techniques that are foreign to Buffy and the gang. This could lead to some cool training scenes and new ways to fight demons. Also, an OC who is a seer with the ability to see not only the future but also the past of supernatural beings could add a new layer of mystery to the story.
For a Buffy the Vampire Slayer OC fanfic, an interesting OC could be a time - traveler. This character could come from the future to prevent a major catastrophe in the Buffyverse. They might have knowledge of future events and technologies that could either help or hinder Buffy's fight against evil. Another option is an OC who is an artist. But their art has a magical quality to it. When they draw something, it can come to life or have an effect on the real world. For example, if they draw a cage, it can trap a vampire. And an OC who is a shapeshifter, able to take on the forms of various mythical creatures to aid in battles.
Another plot could involve a male OC who is a vampire hunter from a long line of hunters. But he has a different approach compared to Buffy. He believes in using more high - tech gadgets along with his physical combat skills. He teams up with Buffy and the Scooby Gang, and there are some clashes at first due to their different methods, but eventually they work well together.
One idea could be a crossover where Naruto's world is invaded by vampires. Buffy could travel to the Naruto universe to help fight them using her slaying skills and knowledge, while Naruto and his friends learn about the existence of vampires.
One idea could be that the half - slayer half - vampire struggles with their dual nature. They might have moments of extreme strength from the slayer side, but then be tempted by the vampire's bloodlust. For example, they could be in a fight against a powerful demon and find that their vampire side gives them an unexpected advantage, like enhanced speed, but they also have to fight the urge to feed on the demon's blood. Another plot could involve them trying to find a way to fully embrace both sides or choose one over the other. Maybe they meet other hybrids and form a group to protect the world in a different way than traditional slayers do.
Some fanfiction ideas could revolve around the origin of Halloween in the Buffyverse. Maybe there was an ancient slayer who made a deal with a powerful entity on a Halloween long ago, and now the consequences are starting to show up again. Or perhaps it could be about a new character who comes to town on Halloween and has a mysterious connection to Buffy's slayer powers. There could also be stories where the villains of the show plan a huge attack on Halloween night, taking advantage of all the chaos and costumes to blend in.
In Buffy the Vampire Slayer fanfiction, there's a popular OC who is a time - traveler. This character can go back and forth in time to prevent major disasters in the supernatural realm. They are often in conflict with the natural order of things but have good intentions. There's also an OC who is a half - demon, half - fairy. This unique combination gives them powers like flight and the ability to cast illusions, which they use to aid Buffy in her battles. Additionally, an OC slayer who was trained in a secret monastery far away and has a very disciplined fighting style is quite popular.
There might be a fanfiction where Dawn travels back in time and meets a younger version of Buffy. This could lead to some really interesting interactions and changes in the timeline.
One interesting fanfiction could be about Spike's redemption arc in an alternate universe. Maybe he meets Buffy much earlier and their relationship develops in a completely different way, with him being more of a reluctant hero from the start. Another could be a time - travel story where Buffy and Spike are sent back to a crucial moment in the show's history and have to change things without messing up the timeline too much. And there are also those that focus on their emotional connection, like a story where Spike has to deal with his love for Buffy while she's in a coma.
One interesting story could be where Buffy meets the Cullens from Twilight. Maybe she initially suspects them of being dark vampires but then realizes they have a different code. Another could be a crossover where the Scooby Gang has to deal with the Volturi's power plays in Sunnydale. There are also fics where Buffy and Edward team up to fight a common vampire foe that is stronger than both their usual adversaries.
Some Xander fanfiction focuses on his love life in a more unique way. He could fall for a new character, a half - vampire half - human girl perhaps. Their relationship would be full of drama as they struggle with their different natures and the Scooby Gang's reactions.