Sure. 'Sonic Meets Equestria Girls' is a popular one. It has an interesting plot where Sonic accidentally enters the world of Equestria Girls and has to find his way back while making new friends.
Another great one is 'Sonic and the Magic of Equestria Girls'. It delves into how Sonic discovers the unique magic in the Equestria Girls' world and how he uses his own abilities to help them out in a tricky situation.
Well, there's also a fanfiction where the Sonic characters get to experience the magic of the Equestria Girls' school. It's really interesting to see how they adapt to the new environment, like Sonic trying to run in the hallways without causing too much chaos. It shows a great blend of the two different worlds and their characteristics.
Friendship is a big one. Just like in the original My Little Pony series, the idea of different characters coming together and forming bonds is common. Sonic, being from a different universe, has to learn to work with the Equestria Girls.
One interesting MLP Equestria Girls fanfiction is 'The Portal's Aftermath'. It explores the consequences of the portal incidents in a very creative way, with great character development for the Equestria Girls.
Another good fanfic is 'The Magic of Friendship in EG High'. This story focuses on how the characters in Equestria Girls high school strengthen their friendship through different magical and non - magical events. It shows how they support each other and grow together.
There's also 'Equestria Girl Meets Sonic'. In this fanfiction, the characters from Equestria Girls cross paths with Sonic. It explores how they would react to each other's different worlds and abilities. It's full of humorous moments as they try to understand one another.
One idea could be a story where the EG characters swap personalities for a day. It would create lots of chaos and funny situations. For example, Sunset Shimmer could become super shy and Fluttershy could be really bold. Another idea is a time - travel fanfiction where they go back to the founding of Canterlot High and have to deal with the first magic - related problems there. They could learn about the origins of the school and how magic has influenced it over the years.
Don't rush the relationships. As I mentioned before, a slow - burn can be really effective. Let the characters get to know each other gradually. Also, add some conflict. It could be jealousy among the harem members, or an outside force trying to break them up. This adds drama and keeps the story interesting.
There's a fanfic called 'Kyle and the Equestria Girls Mystery'. In this one, Kyle teams up with the Equestria Girls to solve a mystery that is threatening to disrupt the balance between the human world and Equestria. It's full of suspense and great character interactions.
One common storyline is Sonic getting transported to the Equestria Girls' world and having to adapt to the new environment. He might have to deal with the different magic and social norms there. Another could be Sonic teaming up with the Equestria Girls to fight a common enemy, like a powerful villain from either his world or theirs. And sometimes, there are stories about Sonic teaching the Equestria Girls about his speed and abilities, and in return, they teach him about friendship in their unique way which is very different from what he experiences in his own world.
One interesting story could be about Sonic somehow getting transported to the Equestria Girls' world and having to team up with the girls to stop a new villain. Maybe he uses his speed to outwit the bad guy while the girls use their magic and friendship powers.