Perhaps a character who has a hidden agenda. It might be someone who appears to be friendly on the surface but has ulterior motives. It could even be a character that Twilight has helped in the past but has turned against her for some reason. Maybe they feel indebted to Twilight and the thought of being in her debt makes them resentful, leading to the betrayal.
It could be a jealous rival of Twilight. Maybe someone who has always been envious of her status and power in Canterlot.
One possible betrayer could be a power - hungry individual. They see Twilight as a threat to their own rise to power in Canterlot. Another option could be a character who is being controlled or influenced by a dark force. This would add an element of mystery and external influence to the betrayal.
One interesting plot point could be how Twilight discovers the betrayal. Maybe she stumbles upon a secret meeting or a hidden letter. Another could be the reaction of her friends. Do they believe her immediately or are they skeptical at first?
Perhaps Twilight is framed for something during the wedding, like stealing an important item or ruining the wedding preparations. This false accusation leads to her being ostracized by others, which is the betrayal she experiences.
In this fanfiction, the idea of Twilight being betrayed during a Canterlot wedding is likely to create a lot of drama. It could involve her friends turning against her or some sort of plot that makes her feel isolated. Maybe it's a miscommunication that leads to the so - called betrayal.
Princess Celestia is often included. She is an important figure in Canterlot and could play various roles in the wedding fanfiction. For example, she might be the one giving Twilight advice or overseeing the wedding arrangements. Then there's Rainbow Dash. As Twilight's friend, she could be involved in some exciting flying stunts during the wedding festivities or helping with last - minute preparations. Pinkie Pie is also a common character. She would surely be in charge of the party - planning aspect of the wedding, making sure there are plenty of delicious treats and fun games.
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.
It could be Luke. Even in a time - travel scenario, Luke's bitterness towards the gods might lead him to betray Percy. He could use time - travel to his advantage, perhaps making deals with past versions of enemies to stop Percy from achieving something that would benefit the gods.
One possible alternate ending could be that Twilight Sparkle uses her magic in a completely unexpected way to stop the wedding chaos and actually uncovers a plot that was much deeper than anyone thought, leading to a celebration of friendship rather than a wedding.
One of the popular themes is friendship. In many Canterlot wedding fanfictions, Twilight's friendships play a crucial role. For example, her friends might help her deal with the chaos that often occurs during the wedding preparations. Another theme could be magic. Since Twilight is a powerful unicorn, her magical abilities can be a central part of the story, like using magic to solve problems or create amazing wedding decorations. Also, love is a key theme. It could be not just the love between the couple getting married but also the love among friends and the love for Canterlot itself, which adds depth and warmth to the fanfiction.
It could be an enemy in disguise. Maybe a Grimm has managed to infiltrate their ranks in a clever way and then betrays the Rose character. Grimm are known for their devious ways and this would be a very RWBY - like scenario.
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.