The characters in 'Harry Potter' are also a reason. Harry himself is an orphan who discovers he has this great destiny in a world he didn't fully know about. His friends Ron and Hermione are also very unique, with different personalities and skills. The relationships between the characters, like the love - hate relationship with Snape, add a lot of depth and complexity. This departure from typical character archetypes in some fanfictions can make it maverick.
The overarching plot of good versus evil in 'Harry Potter' is told in a very engaging way. It's not just a simple fight between the good guys and the bad guys. There are layers of mystery, like the secrets of Voldemort's past and the prophecies related to Harry. The way the story unfolds over seven books, with each book adding more pieces to the puzzle, is a maverick approach compared to many fanfictions that might have more straightforward plots.
One aspect could be its unique and complex magical world. It has a vast array of spells, magical creatures, and wizarding traditions that are very distinct. For example, the concept of the four Hogwarts houses with their own characteristics and the sorting hat that decides which house a student belongs to. This kind of creative world - building is what sets it apart and might be considered maverick in the realm of fanfiction.