Well, it could be about Fem Daisuke breaking a promise to a close friend in the fanfiction world. Maybe she promised to keep a secret but then revealed it, causing a lot of trouble and hurt feelings among the characters.
Perhaps in the fanfiction, Fem Daisuke betrays a group she was part of. She could have been influenced by an external force, like a new character who manipulates her into turning against her former allies. This could lead to a series of events where she helps the enemy in some way, such as giving away strategic information. As a result, her former friends now have to deal with the consequences of her betrayal and also figure out how to stop her if she has gone too far on the wrong side.
In the context of this fanfiction, Fem Daisuke might betray a love interest. She could have started to develop feelings for someone else and in the process, she betrays the trust of her original love. For example, she might lie about her whereabouts when she's actually spending time with the new person she's interested in. This would not only break the heart of the first love but also create a lot of drama and conflict in the story.
She could betray her mentor. In many fanfiction stories, a mentor - student relationship is crucial. If Fem Daisuke betrays her mentor, it could be a huge turning point. Maybe she steals an important item or knowledge from her mentor that was meant for a greater good and uses it for her own selfish purposes.
One possible plot could be that the godlike fem Harry Potter is betrayed by the wizarding establishment. They see her as a threat due to her immense power. So they conspire against her, which leads her to go into hiding. While in hiding, she discovers secrets about the wizarding world that were meant to be hidden and she uses this knowledge to fight back against those who betrayed her. She may also form new alliances with outcasts or creatures that were also wronged by the wizarding society.
Redemption is also a possible theme. Maybe the person who betrayed Fem Natsu realizes their mistake and tries to make it up to her. The fanfiction could then focus on whether Fem Natsu can forgive and allow for redemption, or if she is too hurt to ever trust that person again. It could also explore how the act of betrayal changes both characters involved in the long run.
A love interest is also a common choice. In fanfictions, love can be a complicated and often treacherous thing. The love interest could have their own motives, like being forced by an external power or having a hidden agenda that conflicts with Fem Robin's goals.
In many such fanfictions, the betrayal of fem Percy can be set up in different ways. Maybe it's a betrayal within the context of the magical world she inhabits. For example, if she's part of a group like the demigods, a fellow demigod could betray her for power or out of jealousy. This then sets off a chain of events where fem Percy has to re - evaluate her relationships and her place in that world.
In a 'cheetara gets betrayed fanfiction', perhaps her closest friend reveals her secrets to her enemies. This could lead to her being in great danger as her foes now know her weaknesses. She might feel isolated and have to struggle alone to overcome the situation.
In a 'Percy and Nico are betrayed' fanfiction, perhaps they are betrayed by the gods. The gods, fearing their growing power, might spread lies about them among the demigods. Percy and Nico then have to fight not only against the false accusations but also the demigods who turn on them. They would have to find a way to clear their names and prove their loyalty.
Well, perhaps in the fanfiction, Percy and Piper are betrayed by a new character who infiltrates their group. This new character might be working for an old enemy, like Gaea's remaining followers. The betrayal could involve the new character stealing important information from Percy and Piper that was crucial for the safety of Camp Half - Blood. As a result, Percy and Piper have to race against time to retrieve the information and expose the traitor.
In this fanfiction, it might be that Sirzechs is being manipulated by some dark force. This dark force convinces Sirzechs that Naruto is evil. As a result, Sirzechs betrays Naruto. Naruto then has to not only deal with the betrayal but also figure out how to stop this dark force that is causing so much chaos and misunderstanding.
Perhaps in this fanfiction, Yugao is secretly working for a hidden organization that wants to get rid of Naruto. She betrays him by revealing his secrets or setting him up in dangerous situations. Naruto, being the kind - hearted person he is, initially doesn't want to believe she would do such a thing and tries to reason with her, but she is too far gone in her loyalty to the other side.