He might know Latin. A lot of magic spells seem to have Latin roots. And also French, as it is a common language in European fanfiction settings. Maybe even Gobbledegook, the language of the goblins.
In fanfiction, Harry could know a variety of languages. For starters, he may be proficient in Parseltongue, which is the language of snakes. This would be very useful when dealing with snake - related magic or creatures. He could also know Ancient Runes, which is more like a symbolic language but still important in the wizarding world. Additionally, languages like Spanish or Italian might be in his repertoire as they are also part of the broader European language family and could be relevant in cross - cultural magical interactions.
One interesting aspect is the creation of new spells in fanfiction using the existing Harry Potter language framework. For example, authors might come up with unique incantations for spells that have different effects than the ones in the original books. Another aspect could be the exploration of how different wizarding cultures within the fanfiction world have their own dialects or accents of the magical languages. It adds more depth to the already rich Harry Potter universe.
In some Harry Potter fanfiction, the flower language of the asphodel could be associated with death and the afterlife, much like in the Potterverse where it's used in graveyards. Another could be the lily, which might represent purity and sacrifice, as it does in the original series with Lily Potter.
Some possible petnames could be 'Hermy', 'Mione' or 'darling Hermione'.
One interesting concept could be alternative timelines. For example, what if Harry had been sorted into Slytherin instead of Gryffindor? It would completely change his relationships and the story's progression. Another concept might be the exploration of different magical creatures that were only briefly mentioned in the original books. Fanfiction often delves deeper into their behaviors and habitats. Also, some fanfictions focus on the backstories of minor characters, like Neville Longbottom's family history before he came to Hogwarts.
The plot could involve Harry being a reincarnation of Anubis. He might start to have strange dreams and visions related to his past life as the Egyptian god. As he tries to understand these, he discovers that his powers as Anubis are starting to surface. This could lead to him having to protect the wizarding world from a new kind of threat that only his combined powers can defeat.
The appeal lies in its creativity. It breaks away from the traditional narrative of the Harry Potter series. People might be drawn to it because it allows for a different kind of character growth for Harry. As a rockstar, he would have to deal with fame, fans, and the music industry, all while still having his magical roots. It can also bring in a new aesthetic, with Harry in rocker outfits and performing in magical concert venues. This kind of fanfiction can offer a fun and unexpected way to revisit the Harry Potter world.
It might entail Harry having Kryptonian powers like super strength or flight while still being a wizard. He could use his magic in combination with his new powers to defeat villains in a more powerful way.
Maybe Gandalf appears in the wizarding world of Harry Potter and helps him to defeat Voldemort. He could use his powerful magic that is different from what they have in Hogwarts.
It might involve Harry using his magical abilities in a sniper - like way. Maybe he uses his wand to aim precisely at enemies, much like a sniper aims a rifle.
In this fanfiction, it might be that Harry Potter finds himself in a situation where he has no choice but to become like the Riddler. Maybe he's trapped in a magical riddle - filled dimension and has to adapt the Riddler's ways to escape. Along the way, he could be using his knowledge of magic and the Riddler's tactics to outsmart the various magical creatures or dark wizards that are also trapped there.