Obviously, Yundle and Granpa are the main characters. They could be two old friends who have known each other for a long time and share a lot of memories.
Maybe there's an old wizard in the fan fiction who becomes their guide or mentor. He has a lot of knowledge about the magical world that Yundle and Granpa are exploring. He helps them understand the strange things they encounter and gives them advice on how to deal with difficult situations.
One idea could be that Yundle and Granpa go on a magical adventure through a forest filled with talking animals. They might encounter a mischievous fox who tries to lead them astray but they use their wisdom and kindness to overcome the fox's tricks.
A young artist and a coffee shop owner. The artist is constantly looking for inspiration and finds it in the cozy atmosphere of the coffee shop. The owner, on the other hand, is intrigued by the artist's creativity and they start a friendship that might turn into something more.
Obviously, Spongebob himself could be a main character. He could be on a quest to find the perfect lemon for his grandmother's lemon pie recipe. Patrick could also be a main character, tagging along with Spongebob and providing his own brand of silly commentary throughout the adventure.
It could be a group of cats. One cat could be the curious and adventurous leader, another could be the cautious one always worried about getting into trouble, and the third could be the funny one who always makes the others laugh during their holiday escapades.
One could make a young journalist the main character. They are assigned to write a story about Lady Liberty and in the process, they discover strange occurrences around the statue. Or perhaps a group of activists who use Lady Liberty as a symbol for their cause could be the main characters. They fight for various rights while being inspired by the statue.
Obviously, the chipmunk with speed would be the main character. But there could also be a wise old owl who serves as a mentor to the chipmunk, guiding it on how to control its new speed.
In a Pokemon Survivor fan fiction, Brock could be one of the main characters. His knowledge of Pokemon care and his ability to cook would be very useful for survival. Additionally, Serena, with her strong bond with her Pokemon and her determination to achieve her goals, could also be a main character. Their different personalities and skills would create a diverse and interesting group dynamic in the story.
An old historian could be a main character. This person has studied the pre - revolutionary American monarchy and believes that it had certain virtues that could be brought back. They use their knowledge to convince others and play a key role in the restoration process, all while having to deal with modern - day skeptics.
The main characters could be the fox, who is a new singer with a mysterious past, and Finn Hudson. The rose might be something that Finn uses to try and win over a girl, but the fox has an interest in it too. They could end up competing for the rose in a way that also involves their musical talents and status in the Glee club.
Andrew Jackson himself could be a main character, of course. And maybe Twilight Sparkle could be another main character. She is very intelligent and curious, and she would be interested in learning about this strange new arrival from another world or time. Their interactions could drive the story forward as they try to understand each other.