One possible plotline could be that Twilight discovers her best friend has been secretly working against her all along and planned something devious for the wedding. Maybe this friend has a hidden jealousy towards Twilight's relationship or her role in the wedding. Another could be that Twilight is betrayed by a new acquaintance who she thought was a friend, but in reality was an enemy in disguise, leading to chaos at the wedding.
In this fanfiction scenario, perhaps Twilight is betrayed by a family member at the wedding. This family member might be jealous of the attention Twilight is getting or has some long - held grudge. They could spread false rumors about Twilight during the wedding, causing her friends and loved ones to doubt her. The betrayal could also be related to a valuable heirloom or a special role in the wedding that was supposed to be Twilight's but was taken away from her through deceit.
Well, it could be that Twilight is betrayed by someone she trusted deeply, like a mentor figure in the MLP world. This mentor might have some ulterior motives related to power or control. They could manipulate events at the wedding to make Twilight look bad or to cause a rift between her and other ponies. It could also involve a spell being cast on Twilight during the wedding, making her act out of character, and everyone thinking she's the one at fault when in fact she's been betrayed.
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.
Well, it could be that Hestia betrays Percy for power. In the fanfiction world, she might see Percy as a threat to her own influence among the demigods or the gods. So she makes a deal with another powerful entity to get rid of Percy. For example, she could give false information about Percy's next move to a group of monsters, causing them to ambush him.
One possible plotline could be that Ash is betrayed by his so - called friends in the Pokémon world. They might spread false rumors about him, making everyone turn against him. Meanwhile, Mewtwo, who has formed an unlikely bond with Ash, is also betrayed by the scientists who created it again. They try to recapture Mewtwo to use it for their evil experiments. Ash and Mewtwo then team up to fight against their betrayers and prove their worth.
One possible plotline could be that Serafall, perhaps influenced by some external force or a misunderstanding, turns on Naruto. Maybe she believes Naruto has some hidden agenda that endangers her or her world. So she starts to undermine Naruto's efforts and even plots against him directly.
Another plotline could be a time - travel story. Twilight accidentally travels back in time to when Sombra was first becoming evil. She tries to change his path and prevent him from turning into the dark villain he became. This would involve her getting to know the younger Sombra and trying to influence his decisions with her knowledge of the future.
A plotline could be that the protagonist is a new pony in Ponyville who catches Twilight's eye. They start to interact more and more, and a romance blossoms. For instance, they meet at the library when the new pony is looking for a rare book.
Well, it could start with Anko being given false information about Naruto. Let's say someone convinces her that Naruto is secretly working with an old enemy of Konoha. She then starts to spy on Naruto. As she does this, she uncovers some things that seem to confirm the false information, but in reality, they are just coincidences or set - ups. So, she feels she has no choice but to betray Naruto to protect the village. It could also be that Anko has her own ambitions that conflict with Naruto's goals for the village, and she sees betraying him as a way to achieve her own ends.
One possible plotline could be that Naruto discovers a deep conspiracy within Konoha that makes him feel betrayed. For example, he might find out that some of the village elders have been using him all along as a tool to gain power. So in his rage, he decides to take revenge on the village. He could start by using his shadow clones to create chaos and disrupt the normal operations of Konoha.
Perhaps in this new region, Ash discovers a powerful new Pokemon that others want to control. His friends, fearing the power of this Pokemon, betray him to protect the region. They might think that Ash is being too reckless with this new discovery and that it could lead to destruction. It could also be that there's a prophecy in the new region that Ash is somehow involved in, and his friends misinterpret it and believe he's the cause of potential harm.
A dark magic - using villain from the MLP universe could also be the one to betray Twilight at the wedding. This villain might have infiltrated the wedding planning under a false guise. They could then use their magic to turn Twilight's friends against her during the wedding, making it seem like Twilight has done something wrong when in fact she is the victim of betrayal.