Well, he could find out he's the heir when he enters the Chamber of Secrets instead of just being a Parselmouth. As the heir of Gryffindor, he might find a way to counter the basilisk's stare with some sort of Gryffindor - related magic. Maybe there's a Gryffindor - branded shield hidden in the school that he discovers and it gives him extra protection against dark magic. Or perhaps he has to face off against an old enemy of Gryffindor's, who has been resurrected, and use the Gryffindor - style fighting skills he uncovers as the heir to win the battle.
One plot idea could be that Harry discovers his heritage as the heir of Godric Gryffindor early on. This could lead to him having special powers or abilities that are associated with Gryffindor. For example, he might be able to communicate with the portraits of Gryffindor more easily and gain wisdom from them. Another idea is that there could be a hidden treasure or weapon left by Gryffindor that only his heir can find and use to defeat Voldemort. It could also involve a quest where Harry has to prove his worthiness as the heir by facing various challenges that test his Gryffindorian traits like courage, chivalry, and determination.
A possible plot is that Harry starts to have strange dreams about Godric Gryffindor. These dreams guide him to a secret room in Hogwarts where he finds Gryffindor's old training ground. There, he learns combat techniques and spells that Gryffindor himself used. This newfound knowledge makes him a much more formidable wizard. He could also find that as the heir, he has a connection to the Sorting Hat that allows him to call on Gryffindor's courage for his friends when they are in danger. This would be a great way to show how his heritage as the heir can be used for good in the wizarding world.
One interesting plot could be Harry Potter being transported back in time and meeting Godric Gryffindor. He could learn about the founding of Hogwarts directly from Gryffindor, like the original intentions behind creating the house system. Another plot might involve Godric Gryffindor's spirit guiding Harry through a difficult task, perhaps when he's facing a powerful dark wizard. It could also be a story where Harry discovers a hidden magic that was once known only to Gryffindor and uses it to save Hogwarts.
Well, a possible plotline is that Harry starts to have dreams or visions related to Gryffindor's past. These could guide him in his fight against Voldemort. For example, he could see how Gryffindor defeated dark wizards in his time and use that knowledge. Also, Harry might face challenges within Gryffindor house itself. Some students could be jealous of his new status, while others might expect him to lead them in a more direct way.
Another plot could involve the heir being hunted by dark wizards who believe that the heir's blood holds special powers. The heir then has to go on a journey to find a powerful magical artifact left by Gryffindor himself to protect their bloodline and the wizarding world from the dark forces.
Well, a big theme is legacy. Since Harry is in Gryffindor house, people like to write about how he lives up to Gryffindor's legacy. Also, the idea of Gryffindor's magical knowledge being passed down to Harry. For example, Harry might learn a special spell or magic technique that Gryffindor created. And there's also the theme of heroism, as both Harry and Gryffindor are seen as heroes, and fanfiction might explore how Gryffindor's brand of heroism influences Harry's own journey.
One common theme is legacy. Since Godric Gryffindor is one of the founders of Hogwarts, fanfictions often explore how his legacy lives on through Harry Potter. Another theme is courage. Gryffindor was known for his bravery, and this is often emphasized in the fanfictions, with Harry either learning about true courage from Gryffindor or showing extraordinary courage inspired by him.
One common theme is courage, which is very much in line with Gryffindor's house trait. Fanfictions often explore how Gryffindor's own courage influenced the events around him and the people he interacted with.
A plot could be that a Gryffindor Animagus accidentally reveals their form during a Quidditch match. This causes chaos as everyone tries to figure out who it is. It also draws the attention of the Ministry of Magic who have strict rules about unregistered Animagi. The character then has to deal with the consequences while also trying to prove they mean no harm.
Well, Harry Potter himself could be a possible heir. He already has so many Gryffindor - like qualities. His courage and loyalty make him a strong candidate.
One interesting plotline could be Harry discovering new magical abilities as the heir of Gryffindor. Maybe he can communicate with the spirit of Godric Gryffindor who imparts ancient wisdom and powerful spells.
Another plot could involve Harry's relationship with the other houses. Since his parents are two of the founders, he feels a sense of responsibility towards all the students. He tries to bridge the gap between the houses, which has been widened by years of rivalry, and in the process, he uncovers a plot by a group who wants to keep the houses divided for their own malicious purposes.