Another plotline might be that Harry gets to influence the Marauders in some way. For example, he could give them a heads - up about future events, which would change the course of their actions. This would then have a ripple effect on the entire Harry Potter timeline, leading to a very different present in Harry's time.
Maybe Harry finds himself in a situation where he has to team up with the Marauders to fight a common enemy that was previously unknown in the original Potter story. This would create a whole new dynamic and show how different generations of Hogwarts students can work together.
Perhaps a plotline where the Marauders' spirits or echoes are awakened in Harry's time at Hogwarts. They start guiding him in his fight against Voldemort. They teach him spells and strategies that they used during their own battles against the Dark Arts. This would give Harry an edge and also create some really heartwarming and funny interactions as he tries to keep their presence a secret from his friends.
Well, in some fanfictions, there are plotlines about the Marauders getting involved in some sort of mystery at Hogwarts that is deeper than the normal school drama. For example, they might uncover a dark secret about one of the teachers or a hidden part of the castle. This could lead to them having to use their combined skills and friendship to solve the problem and keep the school safe.
One interesting plotline could be the identity of the masked marauders. Are they related to the original Marauders? Maybe they are descendants with a new mission. Another could be their interactions with Harry and his friends. Do they help or hinder Harry in his fight against Voldemort? It could also be about the secrets they hold that are related to Hogwarts' past, which could be a major factor in the story.
Another plotline could involve Petunia getting involved in one of the Marauders' adventures by accident. Maybe she stumbles upon them while they are exploring a secret part of Hogwarts and has to work with them to get out of a tricky situation.
Perhaps a plotline where Ginny accidentally travels back in time and actually meets the Marauders. This would lead to a whole series of adventures as she tries to fit in with their group, while also trying not to change the future too much. She might have to help them with some of their pranks against Snape without making things worse between them.
In some fanfictions, there could be a plotline where Harry Potter discovers a hidden connection between himself and Grindelwald. Maybe through some ancient magic or a family secret. This connection then leads to a series of events where they must interact and understand each other better. For example, they might have to exchange magical knowledge to solve a mystery that is plaguing the wizarding community. Or perhaps Harry has to enter Grindelwald's mind to find a way to defeat a common enemy, which is a very mind - bending and exciting plot.
One interesting plot could be Harry time - traveling and getting to join the Marauders on one of their pranks at Hogwarts. He might learn some new spells and mischief - making techniques from them.
One interesting plotline could be how Harry's personality is shaped differently. With the Marauders' influence, he might be more mischievous and confident. For example, he could learn pranks from them at a very young age and use them to outwit his enemies later on.
A great plotline in such fanfics is when Harry has to deal with the time - travel paradoxes. Since he's in the Marauders era, any change he makes could have a huge impact on his own future. He might be hesitant to do too much at first. Also, his relationships with the Marauders are fascinating. He could become like a mentor figure to them in some ways, teaching them things he learned from Dumbledore. And the whole idea of him being in a world where Voldemort is still rising but in a different stage is full of potential for exciting story development.
One interesting plotline could be Harry trying to prevent the death of his parents. He might use his knowledge from the future to change certain events. For example, he could try to stop Voldemort's rise to power earlier in the Marauders' time.