It could be about Harry, Ron and Hermione's careers. Maybe Harry is now a high - ranking Auror, leading teams to fight the remaining dark wizards. Ron could be running Weasley's Wizard Wheezes successfully, and Hermione might be making great changes in the Ministry of Magic with her intelligence.
The main characters are often the children of the original Harry Potter characters. For example, Albus Severus Potter, James Potter, and Lily Potter. Also, Scorpius Malfoy is usually a central character as he is part of the new generation at Hogwarts.
In '19 years later' in Harry Potter fanfiction, we might see the next generation of wizards at Hogwarts. Harry's kids could be getting into all sorts of adventures, just like he did. Maybe they'd be facing new threats to the wizarding world.
The children of Harry, Ron, and Hermione would likely be main characters. For instance, Harry's son could inherit his father's courage and be at the center of a new mystery. He might have to deal with the high expectations placed on him because of his father's legacy.
One possible storyline could be the children of the original characters starting their own adventures at Hogwarts. They might face new threats that are related to the past but in a different way. For example, a new dark wizard could be trying to revive the ideas of Voldemort and the kids have to stop it using the knowledge passed down from their parents.
Hermione Granger would be a likely main character. She has always been a central figure. Maybe she's working on some revolutionary magical research or is involved in political reforms in the wizarding world. Her relationship with Ron and their family life could also be part of the story.
Newly discovered magical families could rise to prominence. These families might have been in hiding or just not known before, but now they play a crucial role in the wizarding world of 1000 years later. Their members could be the main characters, bringing in fresh perspectives and magical abilities that were previously unheard of.
Well, some fanfictions might focus on the magical education system evolving over the 19 years. Maybe there are new subjects being introduced at Hogwarts. Also, the friendship dynamics among the new generation of students could be a great plotline. For example, how they form inter - house friendships which were not as common in the past.
Common themes in '19 years later' Harry Potter fanfiction include the exploration of new friendships. Just as Harry had his group, now the new kids are forming their own bonds. Another theme is the discovery of the past. The new generation might be uncovering secrets or stories from the past battles and events that their parents were involved in. And of course, there's the theme of magic evolving. New magical abilities or uses of magic might be introduced as the wizarding world progresses.
The relationship between wizards and Muggles could be entirely different. Maybe after a thousand years, there is no more secrecy, and wizards and Muggles live together in harmony, with wizards using their magic to help improve Muggle technology and vice versa.