Perhaps in the fanfiction, Harry has an encounter with a mysterious magical creature early in his life that imparts special knowledge of magic to him. This early knowledge gives him an edge in his Hogwarts studies and adventures, like being able to solve complex magical puzzles with ease.
In some 'Harry Learns Magic Early' fanfictions, Harry might accidentally stumble upon an ancient magic ritual that accelerates his magical learning. As a result, he is able to perform complex spells during his first year at Hogwarts, which causes a stir among the teachers and students alike. He may use this early - learned magic to protect his friends from dark forces that target him earlier than in the original story.
Well, perhaps Percy discovers a hidden magic within himself that he didn't know he had. Maybe he starts off struggling with basic spells and then gradually masters more complex ones. For example, he could be trying to make objects levitate at first and later on be able to conjure powerful shields.
One interesting plot could be Harry accidentally using magic in front of Muggles before he goes to Hogwarts. This would create a whole new set of challenges as the wizarding world would have to cover it up to avoid the Statute of Secrecy being broken.
Obviously, Harry Potter is the main character as the title implies he is the one learning magic early. But there could also be Hermione and Ron. Hermione might be intrigued by Harry's newfound knowledge and Ron could be both a bit jealous and in awe of Harry's early magical abilities.
One possible plotline could be Harry's internal struggle. As he learns dark magic, he has to battle his own moral compass. He might question the boundaries of good and evil. Another could be how his relationships change. His friends might be horrified or try to save him from the dark path.
Another plotline could involve Harry learning ancient magic related to elemental control. For example, he learns to master fire magic in an ancient way that is much more powerful than the regular spells. This newfound power helps him in battles against Voldemort's followers, as he can create massive walls of fire or send out fire - based attacks that are difficult to counter.
In this type of fanfiction, a great plotline could be that Harry stumbles upon a hidden family grimoire. Inside, he finds magic that was thought to be lost. For example, there could be spells for creating protective shields that are stronger than any known spell. Or perhaps he discovers family magic that is related to time - travel, which he then has to learn to control carefully so as not to disrupt the timeline. This discovery of family magic would add a whole new layer to his character development and his role in the wizarding world.
Another idea could be Harry learning magic from a time - traveling wizard from a far - off future. This would introduce futuristic magical concepts and technologies that he would have to adapt to. It could also lead to him having to use his traditional Hogwarts magic in new and unexpected ways to keep up with the advanced magic he's learning.
One interesting story could be Harry's initial struggles. He might face challenges like accidentally causing chaos as he tries to control his wandless magic. For example, he could make objects fly uncontrollably in the Gryffindor common room. Another aspect could be his secret training sessions. He might find a hidden place in Hogwarts, like an abandoned classroom, to practice without others knowing.
There are fanfictions where he learns elemental magic in a new way. For example, being able to combine fire and water magic in a unique and powerful way that was not explored in the original books. He could use this to create new defensive or offensive spells against dark wizards.
One interesting plotline could be Harry discovering a new and ancient form of magic that was lost for centuries. This could lead him on a journey to understand its origin and how to master it.