It could be a fanfic where Harry has a natural talent for potions that he develops over time, outshining his classmates in this area.
One possibility could be a story where Harry discovers a rare potion recipe and masters it, using it to solve difficult problems at Hogwarts.
Often, they show Harry being confident in the potions classroom, which is a contrast to his original somewhat - nervous self. He might also be more respected by Snape, or at least not constantly picked on.
In a lot of these fanfictions, it could be that Harry has a secret mentor. This could be an old wizard who has been secretly guiding Harry in potions, away from the prying eyes of the Hogwarts staff. This mentor could have seen Harry's potential early on and decided to help him develop his skills in private. Another aspect could be that Harry's own determination and his need to prove himself in a different area other than Quidditch or fighting Voldemort drives him to secretly practice and become good at potions. Also, the idea that there are hidden aspects of magic within him, perhaps related to the founders of Hogwarts, that only manifest in his potions - making ability.
Yes, there are quite a few. You can check out fanfiction websites like FanFiction.net or Archive of Our Own. Just search for 'Harry is good at potions' in their search bars, and you'll likely find some interesting stories.
One common plotline is that Harry's potion - making skills earn him a special place in Snape's class. For example, he might discover a new potion ingredient or brewing method that no one else knew. Another is that his skills lead to him getting involved in some sort of secret or mystery related to potions, like an old potion recipe that holds a key to a hidden treasure.
In some fanfictions, Harry might be good at potions because the author wants to give him a new skill set. It could be that they want to show his growth and development in a different area than in the original books. Maybe he has a secret mentor or he discovers a hidden talent within himself through some unique experiences in the fanfiction world.
In some fanfics, Snape may use a potion similar to the Felix Felicis, the luck potion. But instead of just bringing luck, this modified version could be used to change Harry's fate or the course of his actions. It could make Harry more inclined to make certain choices that Snape desires. Also, there could be a potion that can temporarily suppress Harry's magic, which Snape might use to keep Harry out of trouble or to protect him in a different way.
Maybe he uses some special ingredients that others don't usually consider. For example, he might find a rare herb in the Forbidden Forest and use it in a potion to enhance its effect.
Harry might like potions fanfiction because it allows him to revisit the world of potions in a new light. Fanfiction often breaks the boundaries of the original story. It can introduce new characters or storylines related to potions. Harry, having his own memories and feelings about potions, would be intrigued by these fresh interpretations. For example, he could read about potions being used in ways he never thought of in the original series, which can be exciting and thought - provoking for him.
In the fanfiction world, it could be a gift from a powerful being. There are many powerful wizards or magical creatures in the Harry Potter universe. Maybe one of them, seeing Harry's importance or just out of kindness, bestowed this immunity upon him to protect him from the potential chaos that love potions can cause.
One great 'Harry good at potions' fanfiction is 'The Potions Prodigy'. In this fic, Harry's natural talent for potions is explored in depth. He has a unique approach to brewing that surprises Snape and earns him new respect among his peers.