Perhaps they form a secret club to compete with other existing clubs at Hogwarts. They could have their own initiation rites and tasks that are related to the Marauders' legacy. For example, they might try to recreate some of the pranks the original Marauders played, but in a modern context, which could lead to all sorts of comical and exciting situations.
One idea could be the new marauders getting into trouble with a new set of magical artifacts that have been hidden in Hogwarts for centuries. They might discover a map that leads to these artifacts, much like the Marauder's Map. Another could be their interactions with the ghosts in Hogwarts in a more adventurous way, like trying to solve a mystery that the ghosts have been keeping for ages.
Well, one idea could be exploring the marauders' earlier days at Hogwarts in more detail. Maybe showing how they formed their tight-knit group and came up with their mischievous plans.
Another plot could revolve around the love interests of the Marauders. For instance, James Potter's pursuit of Lily Evans. You could show their early interactions, the misunderstandings, and how their relationship gradually developed. It could also include how his friends supported or sometimes complicated his efforts to win her over.
A great plot idea could be Harry getting involved in the Marauders' pranks but also using his experiences to guide them towards more responsible magic use. He could also be a key figure in uniting different groups in the wizarding world during that time. Since he has a different perspective, he might be able to bridge the gap between pure - bloods, half - bloods, and Muggle - borns much earlier, which could have a huge impact on the future and the fight against Voldemort.
Well, it could be some new students who are very much like the original Marauders in terms of their mischievous nature and loyalty to their friends. Maybe a Gryffindor with a great sense of adventure, a Hufflepuff who is unexpectedly brave and loves to get into fun, a Ravenclaw with a brilliant mind for coming up with pranks, and a Slytherin who has a soft spot for his new group of friends.
One idea could be that in this new order, Hogwarts starts accepting students from all magical creatures, not just witches and wizards. This would lead to a whole new dynamic in the school, with different cultures and magic types interacting.
Well, in a 'new normal' Harry Potter fanfic, perhaps the Ministry of Magic decides to open up more to the Muggle world in order to promote better relations. So, Hogwarts starts an exchange program with some Muggle schools. This would bring a whole new set of challenges and friendships. Also, the way Quidditch is played could change. Maybe there are new safety regulations for players, like wearing special protective charms all the time.
One idea could be that the new generation discovers a time - turning device left by Hermione. They travel back to the time of the first Triwizard Tournament. There, they meet a young Sirius Black and Remus Lupin, and get involved in the mystery surrounding Cedric Diggory's death in a new way.
Well, you could have a fanfic where Voldemort uses DND - style dark magic to open portals to other dimensions. The Order of the Phoenix has to quickly learn DND - style combat and magic rules to fight off the new threats that come through these portals. Harry could be sent on a special mission to find a DND - style mage who can teach them the counter - spells. Meanwhile, the Death Eaters are also trying to master this new form of magic for their own evil purposes. This would create a really exciting and unique story.
Perhaps a plot where the protagonist can choose to either side with the Ministry of Magic during a time of political unrest within the wizarding world or join a rebel group. This would involve different magical battles and moral dilemmas depending on the choice. In the 'harry potter cyoa fanfic', this could show different aspects of the wizarding society that we don't often see in the original books.
A cool plot for a Harry Potter Twilight fanfic could be a competition. The wizards from Harry Potter and the vampires and werewolves from Twilight compete in a series of challenges. These challenges could test both magic and the unique abilities of the Twilight characters. Or perhaps a love triangle between a Harry Potter character, a Twilight vampire, and a Twilight werewolf. It would be interesting to see how the different cultures and powers interact in matters of the heart.