Another plot could be that Anakin, without Jedi training, still has a connection to the Force but doesn't understand it. He might have strange dreams and premonitions that he tries to make sense of on his own. This could lead to him seeking out different kinds of mentors, not Jedi, but perhaps old hermits or wise women in the deserts of Tatooine who have a different perspective on the Force.
Another plotline could be that Mace is facing some sort of political trouble within the Jedi Order. Anakin, with his unique position and skills, steps in to help Mace clear his name or resolve the situation. For example, Anakin might use his relationship with Palpatine to uncover some secrets that can exonerate Mace. This would involve a lot of political intrigue and character - driven drama.
I'm not sure specifically as there could be many different takes in such a fanfic. But generally, it might involve Plagueis using his dark side knowledge and skills to train Anakin, perhaps leading Anakin down a different path in the Force compared to his canon training. Maybe Anakin would learn unique Force abilities or have a different view of the Sith and Jedi conflict.
One possible plotline could be that Anakin is somehow brought back to the time when Ben and Rey exist. Maybe he serves as a mentor to both of them, using his own experiences of the dark and light sides of the Force. He could help Ben fully turn back to the light, and teach Rey some ancient Jedi techniques that were lost in her own training.
Anakin's mother, Shmi, would likely be a very important character. Since Anakin is not being trained as a Jedi, he would be more focused on his family. Shmi's influence on Anakin would be even greater, and she could play a role in guiding his actions and decisions, especially in relation to the local community on Tatooine.
Perhaps in this fanfic, Anakin has developed some sort of new power or ability that protects him from getting burned. It could be related to his connection with the Force. He might have found a way to manipulate the Force in such a way that it forms a protective shield around him when the threat of burning is imminent. This new power could be a result of his continuous exploration and growth in the Force.
The main characters would be Anakin Skywalker and Darth Plagueis. Anakin, a powerful Force - sensitive, is the focus of the training. Darth Plagueis, a Sith Lord, brings his knowledge of the dark side of the Force to the table. There may also be other supporting characters like the Jedi who might notice Anakin's change in behavior or Padmé, Anakin's love interest, who could be affected by his new training and the path he is on.
Perhaps in the fanfic, Anakin losing his arm is a turning point. Padmé, seeing his pain and the path he might be headed towards, decides to take Luke and hide away. But Anakin, consumed by his own loss and the dark side tugging at him, tries to find them. This could lead to a cat - and - mouse type of plot where Padmé is constantly on the run, trying to protect Luke from Anakin who is slowly losing himself more and more.
One possible plotline could be Harry initially being forced into the training but then gradually getting intrigued by Grindelwald's knowledge. He might start to question the traditional teachings of Hogwarts. Another could be that Harry is tricked into the training, thinking Grindelwald has good intentions only to discover the truth later.
In a Star Wars fanfic where Anakin was trained by Yoda, Anakin might have better control over his emotions. Yoda's wise teachings could have steered Anakin away from the dark side. He might have learned more about the Force in a balanced way, rather than being influenced by Palpatine's dark whispers.
One possible plotline could be that in a moment of relaxation among his friends, they discover that Anakin is extremely ticklish on his feet. His friends, perhaps Padmé and Obi - Wan in a more light - hearted AU (Alternate Universe), start tickling his feet as a form of friendly teasing. This leads to Anakin chasing them around playfully, creating a comical and warm - hearted scene that shows a different, more carefree side of the usually serious Jedi.