A more complex plot could be that Danny has been having strange dreams about a different magical world, which turns out to be the world of Harry Potter. As they meet and learn they are brothers, they have to navigate their two families and worlds. Danny has to deal with the wizarding family he never knew, and Harry has to understand Danny's life as a half - ghost. They also have to figure out how their combined powers can be used for good, and how to keep their new - found family a secret from those who might use it against them.
One idea could be that they discover their brotherhood through some magical event that links their two very different worlds. Maybe a magical object from the Harry Potter universe shows up in Amity Park and Danny's investigation leads to the revelation that they are related.
Maybe they discover they are brothers through some supernatural or scientific means. At first, they don't get along as they have very different personalities. Danny is more laid - back while Damian is intense. But as they face challenges together, they learn to trust and rely on each other.
One idea could be a crossover where the magical world of Harry Potter intersects with the ghostly realm of Danny Phantom. Maybe Danny gets accidentally transported to Hogwarts and has to navigate the strange new world of magic while also dealing with his own ghost powers. He could form an unlikely friendship with Harry Potter and together they face a new threat that combines elements from both their universes.
One idea could be that Danny discovers a new ghostly power that he uses to take revenge on a group of bullies who have been tormenting his friends. He could use his intangibility in a creative way, like sneaking into their lockers and making their things disappear.
One idea could be Danny Fenton having to deal with a new ghostly enemy that can manipulate time, making his double life as Danny Phantom even more chaotic. Another could be Danny trying to balance his high school life, including exams and relationships, while also facing a ghost invasion that only he as Danny Phantom can stop. Or perhaps a story where Danny Phantom discovers a hidden power within himself that has a connection to his human side, Danny Fenton.
One idea could be a crossover where Danny Phantom and the Robin Brothers team up to fight a common enemy from their respective universes. Maybe a powerful ghost is causing chaos in Gotham and the combined skills of Danny's ghost powers and the Robins' combat and detective abilities are needed to stop it.
One idea could be that Danny gets an illness that affects his ghost powers. For example, he might start losing control over his intangibility or invisibility. This could lead to some really comical or dangerous situations. Another idea is that his friends try to find a cure for his strange ghost - related illness while also keeping it a secret from the town.
Well, imagine if there was a device in the Danny Phantom universe that malfunctioned and created a portal to the Harry Potter world. Danny ends up at Hogwarts during the Triwizard Tournament. He gets involved in the tasks because his powers are seen as an advantage. He might team up with Harry and use his intangibility to pass through obstacles in the maze during the third task. At the same time, he could teach Harry some of his skills, like how to quickly phase through walls to avoid danger.
Well, a great plot for Danny Phantom future fanfiction could be that Danny discovers a way to travel to different dimensions in the Ghost Zone. In these dimensions, he finds versions of himself with different powers and personalities. He then has to figure out how to use this knowledge to save his own dimension from a powerful ghost that is slowly draining the life force of the living world. It could involve a lot of self - discovery for Danny as he learns from his other - selves.
Maybe Ophelia has some sort of special power herself that she doesn't know about until she meets Danny Phantom. They could go on a journey to figure out what her power is and how it can be used to help the town. It would be a great way to explore both of their characters in a new light.
One idea could be that Danny discovers a new power that has been dormant all this time. Maybe it's a power related to time manipulation, which could lead to some really cool adventures where he has to fix time - related problems in the Ghost Zone or in the human world. Another plot could involve Danny meeting his future self who has come back to warn him about a great danger that is coming. This could create a lot of mystery and suspense as they try to figure out what the danger is and how to stop it.