Definitely Twilight Sparkle, since she is such an important pony in the My Little Pony universe and would likely be involved in any big event like a Canterlot wedding. Fluttershy could also be a main character. Her gentle nature could add a different dynamic, perhaps she's helping with the flower arrangements or calming nervous ponies. And then the two ponies getting married should be main characters. Their love story and the events leading up to the wedding could be the focus of the fanfiction.
The main characters could be Princess Cadance, who is often associated with Canterlot and weddings. Shining Armor, her groom, would also be a central figure. Then, Pinkie Pie could be a main character as she always brings fun and chaos to any situation. She could be in charge of the entertainment at the wedding. Another possible main character is Rarity. Given her love for all things glamorous, she might be the one designing the wedding outfits and making sure everything looks perfect for the big day.
Twilight Sparkle is often a main character. She's the smart and studious pony, and at a Canterlot wedding, she might be involved in making sure everything goes smoothly or solving any problems that arise.
One interesting plot could be the addition of new characters to the wedding scene. For example, a long - lost relative of one of the main ponies shows up and causes some chaos but also adds a touch of mystery and family drama.
One interesting plot idea could be a mystery during the wedding. For example, a valuable item goes missing right before the big moment. Another could be a character from the guests' past shows up unexpectedly and has some unresolved issues with the bride or groom. A third idea might be that there are some magical mix - ups that cause comical chaos during the ceremony.
Sunset Shimmer is extremely popular. She has a complex backstory, having once been a villain but then redeemed herself. Her journey of self - discovery and growth makes for great fanfiction material. Then there's Twilight Sparkle, who brings her book - smart and sometimes naive personality to Canterlot High. Also, Rainbow Dash with her competitive and loyal nature is often a favorite. She can be involved in sports - related plots or stories about loyalty among friends.
Twilight Sparkle could be the main character. She was deeply involved in the Canterlot Wedding, and if there was some sort of misunderstanding or mistake on her part, she might be the one to offer an apology in the fanfiction.
Obviously, the Ghost Rider could be a main character. He would bring his unique powers and his dark, brooding personality to the story. Twilight Sparkle could also be a main character. She's very intelligent and curious, so she would be the one to try and figure out who the Ghost Rider is and how he can help or harm Equestria.
The Doctor from Doctor Who would be an amazing crossover character. He could arrive in his TARDIS right in the middle of the wedding preparations. He could then use his knowledge and skills to solve any problems that arise, like a strange alien invasion that targets the wedding. His time - traveling abilities would also add an extra layer of excitement to the story.
In some fanfictions, Twilight Sparkle and her friends could also be main characters. Since the Dazzlings' actions often intersect with the main group in Equestria. For example, Twilight might try to understand the Dazzlings' motives and find a way to either stop them if they are causing trouble or help them if they are trying to reform. The other ponies like Rainbow Dash, Pinkie Pie, etc., would also be involved in different ways depending on the plot. They might be the ones who first notice the Dazzlings' presence and the strange effects their music has on the ponies in Ponyville.
Twilight Sparkle would likely be affected as she is often at the center of things in the MLP universe. Her actions and decisions would be crucial in any alternate ending, whether she's saving the day or facing new challenges.
Another option could be Rainbow Dash as a main character from My Little Pony. She is bold and adventurous, always ready for a challenge. In the Land Before Time, Spike could be a main character. Spike, being a dragon in the pony world, could have an interesting connection with the dinosaurs. He could share his knowledge of different species (from his experience with ponies and other magical creatures) with the dinosaurs, while also learning from them about their ancient ways.