One idea could be that Harry discovers his true parentage as the son of Zeus while at Hogwarts. This could lead to him having new powers, like the ability to control lightning. He might use these powers to defend Hogwarts in a new and unexpected way during a battle.
In the fanfic, Harry's status as the son of Zeus could cause a stir in the wizarding world. Some might fear his new - found power, while others see him as a great asset. This could lead to political intrigue as different factions try to either befriend or oppose Harry, adding a whole new layer of drama to the story.
Perhaps Harry, as the son of Zeus, has a connection to the Greek magical world as well. He could be visited by Greek demigods who help him understand his heritage and train him in using his Zeus - given powers. This would create an interesting crossover between the Harry Potter universe and Greek mythology within the fanfic.
Well, perhaps in the fanfic, Percy is wrongly accused of a crime by Zeus. He then has to go on the run, all the while trying to clear his name. Along the way, he teams up with some unlikely allies, like a group of nymphs who have their own reasons for helping him. As he's on the run, he uncovers a conspiracy within the Olympian council that could change the fate of the demigod world forever.
Well, in this fanfic, a possible plot is that Harry's heritage as the son of Anubis makes him a target for dark wizards who want to use his unique powers. He then has to go on a journey to find out more about his father Anubis and the Egyptian magic that runs in his blood. Along the way, he might meet some Egyptian wizards or witches who teach him things that are completely different from what he's learned at Hogwarts.
Yes, there are likely fanfics out there with this concept. The Harry Potter and Percy Jackson fandoms are both large, and some fans like to cross over the two universes in fanfiction. You can try searching on fanfic platforms like Archive of Our Own or FanFiction.net.
One idea could be Percy having to prove himself to Zeus. Since he's his son in this fanfiction, Zeus might be overly critical. Percy could go on a quest to retrieve a powerful artifact that was once Zeus's but was lost. Another plot could involve Percy's relationships with other demigods changing. They might be jealous or in awe of his new status as Zeus's son.
Well, in such a fanfic, Harry would have a whole new origin story. He could have abilities like super strength or the ability to fly without a broom, coming from Zeus. His connection to the wizarding world might be tenuous as he discovers his true divine parentage. He might also attract the attention of other Greek gods and goddesses, which could lead to all sorts of adventures and challenges that are very different from the original Harry Potter plot. There could be epic battles between magic and divine powers, and Harry would be caught in the middle, trying to figure out his place in both worlds.
Perhaps a plot where Harry son of Eris is on a quest to find out more about his mother Eris. Along the way, he teams up with some unlikely allies. They might have to go through dangerous places like ancient tombs or forgotten magical forests. His powers could be both a help and a hindrance in these situations. For instance, his ability to create chaos might open up paths that were previously blocked, but also attract unwanted attention from dark creatures.
Another idea is a story where Percy discovers a hidden prophecy related to his birth. In this fanfiction, he might have to team up with some unlikely allies, like a group of minor gods who are also interested in the outcome of the prophecy. The story could involve Percy learning more about his parents' relationship and how it has shaped his own destiny.
A great plot could involve Percy discovering a hidden power within him due to his relation to Zeus. He then has to learn to control it while also dealing with the envy of other demigods. For example, he might accidentally cause some chaos in the camp which makes others suspicious and jealous of his new - found abilities.
One idea could be Harry using his Poseidon - given powers to control water in the Triwizard Tournament. For example, in the second task, instead of using gillyweed, he could manipulate the water to his advantage.
A possible plot could involve Harry being drawn to the Underworld to learn more about his mother. There, he meets various figures from Greek mythology who either help or hinder him. His Hogwarts friends might not understand what he's going through, leading to some tense relationships as he tries to balance his two very different worlds.