Well, he could discover new magical abilities or knowledge. Since Hogwarts has a vast curriculum, when Harry gets serious, he may delve deeper into subjects like Ancient Runes or Arithmancy, unlocking secrets that were previously overlooked. This could also lead to him making new friends who share his new - found academic interests. For example, he might become closer to Hermione in a different way, as they study more advanced topics together. He could also start to influence his classmates to take school more seriously as well, creating a positive academic environment in Gryffindor.
He becomes more responsible. Instead of getting into as many impulsive adventures, he focuses on his studies and the duties that come with being a student at Hogwarts.
There's a possibility that he'll face new challenges. It could be a place full of dark magic or dangerous creatures. Harry would have to use his wits and skills to overcome these challenges, and this could be a great opportunity for him to grow as a wizard.
He could find himself in a really tough situation. For example, if he's in the middle of a feud between two magical factions in the fanfiction. He would have to use his wits and skills to try and find a way out or a solution that satisfies both sides. He might also start to question his own beliefs and loyalties as a result of being in this middle position.
Well, in such a fanfiction, Harry might end up in a different house than Gryffindor. He could be resorted into Slytherin, which would completely change his relationships. For example, his friendship with Ron and Hermione might be strained as they are in Gryffindor. And he'd have to deal with the Slytherin stereotype and make new friends among them.
In this fanfiction, Harry might be publicly scolded by the Howler in a really embarrassing way. Maybe it reveals some secrets about him that he didn't want others to know, like his insecurities or small mistakes he made.
One possibility is that Harry is being bullied at the Muggle school, and Hermione stands up for him. She's smart and brave, even at a young age. This act of kindness makes them friends. They then might start to suspect that there's something more to their world than just what they see in the Muggle school. They could begin to exchange stories about their families and how they feel like they don't quite fit in, which eventually leads them to discover their true identities as wizards.
In some cases, when Dexter gets caught, the people who catch him might try to rehabilitate him. They could think that there's still some good in him and attempt to change his ways. However, Dexter might resist this change as his nature is deeply ingrained. This could lead to a power struggle between him and those who want to reform him, creating a lot of drama and tension in the fanfiction story.
Maybe he'll go on a rampage in the fanfiction world. He could start using his powerful jutsu to show his anger, like unleashing a Rasengan on the source of his annoyance.
He could use his ninja skills to fight back. Naruto has a wide range of jutsu at his disposal, like the Rasengan. So, he might quickly launch a counter - attack to protect himself.
Well, it's possible that Harry gets a gadget that can translate any magical language instantly. This would be really useful when he's dealing with ancient spells or communicating with magical creatures from different regions. It could also lead to some comical situations, like when the gadget misinterprets a spell and creates a chaos of unintended magic.