Another difference could be in the magic system. Maybe in the fanfic, there are new spells or the way magic is learned and used is different. For example, instead of using wands, they might introduce a new way of casting spells, like through hand gestures only. This would create a very different feel to the magic in the Harry Potter universe.
Well, in canon, Sirius doesn't really get the chance to fully raise Harry. But in fanfics, he can be a positive male role model. For example, he might teach Harry some dark arts defenses that he didn't learn at Hogwarts. Also, he could introduce Harry to different parts of the wizarding world that Dumbledore kept him away from in the original story.
In the canon, Harry has his moments of doubt and vulnerability. But in confident Harry Potter fanfiction, he's more self - assured. For instance, in canon, Harry might be hesitant to trust new people, but in fanfiction, a confident Harry could be more open - minded. This changes the flow of the story as he interacts differently with both friends and foes.
In canon, Harry has his fair share of hardships but not this kind of extreme abuse. In these fanfictions, the situations are much darker. Canon focuses more on the battle against Voldemort, while the fanfictions focus on Harry's personal and often very difficult experiences with abuse. Also, the relationships in canon are more positive overall compared to the strained and often negative ones in these fanfictions.
Canon Harry Potter is often seen as a hero who follows the rules and values of the wizarding world. However, in dark godlike fanfiction, he may break the rules more freely. He could have powers that are not part of the normal magical repertoire in the books. His relationships with other characters can also change drastically. For instance, his friendship with Ron and Hermione might be strained as his new powers and 'dark' nature set him apart. He may also view the Ministry of Magic in a different light, perhaps as an obstacle to his new - found power and goals.
In old man Harry Potter fanfiction, one big difference from canon is his role. In the original books, he was a young hero, but in fanfics, as an old man, he often becomes a mentor figure. For example, in many fics, he teaches the new students at Hogwarts things he learned the hard way.
It differs from canon mainly in perspective. In canon, we follow Harry's journey mostly. But in 'stepping back' fanfiction, we might see the story from a side character's view. For example, we could see the Triwizard Tournament through Cedric Diggory's eyes. Also, the timeline can be altered. Canon has a set sequence of events, but fanfiction can change when certain things happen. For instance, if the Chamber of Secrets was opened earlier.
It often differs in the sense that it allows for more creative interpretations. Canon is quite fixed, but in a fanfic, the author can make Harry say things or have experiences that might not be in the original books. For example, he could have a different view on a particular spell or a character.
It differs mainly in the language aspect. While most fanfics focus on the regular English - speaking Harry Potter world, this one has Harry speaking Latin. This gives it a more academic and arcane feel. Other fanfics might center around relationships or new adventures, but this one could potentially explore the deeper, more ancient magic through the use of Latin.
The plot in criminal Harry Potter fanfiction is different from canon as it delves into the seedy underbelly of the wizarding world. While canon mainly shows the school life at Hogwarts and the fight against Voldemort's tyranny, criminal fanfiction might introduce new criminal organizations or gangs that operate secretly. These could be made up of characters from different houses or even former Death Eaters and Order of the Phoenix members who have turned to a life of crime. This creates a much more complex and morally ambiguous plot compared to the relatively clear - cut plotlines in the original series.
In contrast to adventure - based Harry Potter fanfics, 'Harry Potter Forced Binding Fanfic' has a more internal and relationship - driven focus. Adventure fanfics usually take the characters on quests and battles across the wizarding world. However, in forced binding fanfics, the focus is often on how the forced binding affects the relationship between the characters. It could be a psychological exploration of how they cope with being tied to someone they may not like or trust at first. This makes it quite distinct from other genres.