He might get injured, like break a bone or get a bad bruise. Then he'd have to go to the hospital wing at Hogwarts for treatment.
Perhaps he falls down the stairs and accidentally discovers a hidden passageway. As he tumbles, he might notice a loose stone or a strange gap in the wall that he hadn't seen before. This could lead him to a secret place in Hogwarts that no one else knew about. It could be filled with old magic items or clues about the history of the school.
Hermione would probably be very worried and rush to his side immediately. She'd start checking for injuries and trying to figure out how to help him.
In a more complex plot, Ginny might be under the influence of a spell that makes her disoriented. She stumbles and falls down the stairs. After the fall, she starts having strange visions. Harry, with the help of Hermione and Ron, tries to figure out what spell was cast on her. They explore the library and old magic texts, eventually finding a way to break the spell and save Ginny from potential long - term harm.
Well, he might get involved in the supernatural drama there. Maybe he'd use his magic to help deal with the vampires and werewolves. He could also make new friends or enemies among the Mystic Falls residents.
One common theme could be the aftermath of the fall. It might focus on Bella's recovery, both physically and emotionally. Another theme could be how the other characters in the story react to her fall. Maybe they show concern, or there could be some mystery about the cause of the fall that the story explores.
In some fanfictions, his fall off the broom could be a turning point in the story. It might lead to him discovering a new magical ability. For instance, he could unconsciously use a form of magic to slow his fall or even levitate himself slightly. This newfound ability could then be explored further in the story, perhaps making him a more powerful wizard in unexpected ways.
Well, he could encounter all sorts of supernatural beings in Mystic Falls. Maybe he'll meet vampires and use his magic to either protect himself or try to understand them. Since he's used to dealing with magical creatures in his own world, he might approach the vampires with a mix of caution and curiosity.
Well, he could potentially join the Avengers. Imagine Harry with his magic skills fighting alongside Iron Man and Captain America. His magical abilities like apparition could be used for quick getaways or surprise attacks during battles.
Well, in such a fanfic, Harry Potter might find himself in the world of Attack on Titan. He could use his magic to fight the Titans in ways the Survey Corps has never seen before. Maybe he'd use spells like 'Wingardium Leviosa' to lift the Titans off the ground or 'Stupefy' to stun them. It would be really interesting to see how his magical abilities would interact with the technology and combat style of the Attack on Titan universe.
The fangirl could be in for a real treat. She may discover unique interpretations of the Harry Potter universe. Fanfics often explore different character backstories or alternative timelines. So, she could learn about what would have happened if Harry had been sorted into Slytherin instead of Gryffindor. She might also encounter new magical creatures or spells that the author of the fanfic has created. And, depending on the type of fanfic, she could be part of a big adventure to save Hogwarts from a new, even more powerful dark wizard than Voldemort.
There could be a situation where Voldemort tries to protect Harry from other threats. For example, he might fight off other dark wizards who want to harm Harry, which is a complete reversal of their normal relationship.