Perhaps Robin is exposed to a new, radical ideology. He meets a group of anti - heroes or villains who convince him that the traditional way of fighting crime in Gotham is ineffective. They persuade him that a more extreme approach is needed. So, Robin turns against Batman and begins to implement this new, more violent ideology in Gotham, causing chaos and challenging Batman at every turn.
One possible plot twist could be that Robin is influenced by a powerful and evil villain. Maybe the villain uses some kind of mind - control device or magic on Robin. For example, the Joker could find a way to make Robin see Batman as the enemy. Robin might then start attacking Batman and helping the Joker with his evil plans.
In a fanfiction where Robin turns evil, it could be due to a personal tragedy. Suppose Robin discovers some dark secret about Batman that he can't accept. This could shatter his trust in Batman and his whole view of justice. As a result, he decides to take a different, darker path. He might start using his skills in more violent and unethical ways, believing that the ends justify the means.
Another plot could be that he is exposed to some sort of mind - controlling substance or technology. The enemy could be using it to turn him against Gotham. Under this influence, he starts to see his friends as foes. He could begin to attack the Bat - family and other superhero allies. His actions would be erratic and violent, and the city would be in chaos as they try to figure out what happened to their hero and how to stop him.
Batman would be heartbroken. He has trained Robin and sees him as a partner and almost like a son. He would first try to talk to Robin, to find out what made him turn evil. He would hope that he could reason with Robin and bring him back to the good side.
Well, one possible plot twist could be that Saitama's boredom turns into a malicious form. Since he's so powerful and always bored from easily defeating enemies, this new evil side might start creating stronger foes just to have a real challenge, but without caring about the destruction it causes. He could also turn against the other heroes, seeing them as weaklings not worthy of his time anymore.
One main plot twist could be that the person who betrays Percy is someone he least expects, like a close friend or family member. This shatters his world and makes him question all his relationships, leading him to turn evil as he feels he can't trust anyone anymore.
In a 'Robin turns into a girl fanfiction', perhaps there's a magic spell gone wrong that causes the transformation. Robin then has to find a way to reverse it. Along the way, he might form new relationships or face challenges in his existing ones. For example, his romantic interests could change or be put to the test.
One possibility could be that he's brainwashed. Maybe a powerful villain uses some mind - control device or magic to turn Robin against his friends. In fanfiction, this could lead to some really intense battles where his former teammates are reluctant to fight him at first, but realize they have no choice.
One possible plot twist could be that Robin discovers the Titans were misled by false information about him. Maybe a villain planted evidence to make it seem like Robin was working against them. For example, the villain could have faked communication records. Another twist might be that the Titans' own insecurities led them to misinterpret Robin's actions as betrayal. Say, Robin was secretly working on a project to protect the team but his secrecy made them suspicious.
One possible plot twist could be Percy's struggle to adapt to the new gender. For example, she might face challenges in how society now treats her. Maybe she was used to certain privileges as a boy that are now different. Another twist could be in her relationships. Her friends might react in various ways, some being very accepting while others are confused or even distant at first. And she could also discover new aspects of herself, like different interests or ways of expressing emotions that were suppressed before.
The plot of a Naruto turns into Sakura fanfiction could involve Naruto experiencing Sakura's emotions more directly. He might feel the pressure she has always felt to keep up with Naruto and Sasuke. This could lead to him understanding her better and trying to change things when he turns back. Also, there could be a situation where Naruto - as - Sakura has to go on a mission alone. This would force him to fully embrace Sakura's skills and personality. He could end up using her intelligence and strategic thinking in ways he never thought possible, which would not only be a growth for the 'Naruto - in - Sakura' character but also an interesting exploration of Sakura's potential.
One possible plot twist could be that Saphira, as a human, has to relearn all her dragon skills in a human form. For example, she might have to find new ways to use her strength or her senses which were so much more powerful as a dragon. Another twist could be that she has to hide her true identity from other humans who might fear or try to use her if they knew she was once a dragon.