One idea could be the twins inventing a new type of magical prank product that has unexpected effects on Hogwarts. For example, it might make the staircases act even more erratically than normal, causing chaos throughout the school.
In some fanfictions, the Weasley twins might befriend a new student who has a special but unusual magical ability. They then help this student develop their skills while also using their new friend's ability to pull off the greatest pranks Hogwarts has ever seen.
One idea could be that Harry and the Weasley twins team up to play a huge prank on Snape. They use a combination of Fred and George's magical inventions and Harry's invisibility cloak to get into Snape's office and rearrange everything in a really chaotic way.
Another plot could be that the OC is a muggle - born with an uncanny ability to see through magical illusions. The Weasley twins, known for their love of creating illusions, initially see the OC as a threat to their pranks. But as they get to know the OC better, they realize that they can use this ability to create even more elaborate and undetected pranks. This would involve a lot of character development for all of them as they learn to trust and rely on each other.
One idea could be Percy trying to understand the twins' pranks and finally joining in on one. Another could be the twins getting Percy to loosen up during a stressful time at Hogwarts, like exam week. Maybe they play a prank that backfires and Percy has to help them fix it without getting in trouble with the professors.
One interesting fanfiction could be about the Weasley twins creating a new line of magical pranks that backfire in hilarious ways. For example, they might make a potion that's supposed to make people's hair change colors randomly, but instead it makes them speak in rhymes for a day.
One idea could be the Patil twins using their unique magical skills, perhaps learned from a different magical culture, to help Harry in a dangerous mission. For example, they might have a special way of divination that gives Harry an edge in predicting Voldemort's moves.
One idea could be that the Carrow twins have a change of heart. Maybe they start to see the wrong in Voldemort's ways after a series of events. For example, they witness an innocent being brutally punished by Death Eaters and it makes them question their loyalty.
One plot idea could be Rose Weasley finding an old diary of Harry's from his Hogwarts days and through it, she discovers a side of Harry she never knew. It could lead to a great adventure as they try to figure out some secrets hinted at in the diary.
Perhaps they form a secret club within Hogwarts where they plan elaborate pranks on the Slytherins. This could involve using their combined knowledge of magic and mischief to outwit their rivals in really creative ways. They might also end up uncovering some dark secrets about the Slytherin common room in the process.
Well, they could be the result of some sort of cross - over experiment gone wrong (but in a good fanfic way). Maybe they have powers from both worlds but struggle to control them at first. For example, they might accidentally cast spells while trying to use their demigod powers. And they could be the bridge between the two groups of friends. The demigods are skeptical of wizards and vice versa, but the twins help them understand each other.
One idea could be that the twins have powers from both the wizarding world and the demigod world. They can use magic spells like in Harry Potter and also have the abilities of a demigod from Percy Jackson. For example, they can control water like Percy and at the same time cast defensive spells. Another plot could be that they are sent on a mission to stop a threat that endangers both the wizarding world and the Camp Half - Blood. They have to use their combined knowledge and skills to succeed.