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.
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.
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.
Obviously, the children of the original characters like James, Albus, and Lily Potter. They are likely to be at the center of many stories as they navigate Hogwarts life. Also, Scorpius Malfoy as he is the son of Draco Malfoy and his story could be intertwined with the Potters.
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.
It could be the original characters from the source material who have now aged 19 years. Their personalities might have changed a bit due to life experiences, but they still carry the essence of who they were.
Most likely the children of the main characters from the original series. Like James, Albus, and Lily Potter. Also, the kids of Ron and Hermione, like Rose and Hugo.
Obviously, Harry and Hermione are the main characters. They are likely to be older, more mature versions of themselves. Harry, with his Gryffindor courage still intact, and Hermione, with her vast knowledge of magic.
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.
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 main characters could be Ladybug and Chat Noir, who are now experienced heroes. However, the fanfiction could also focus on a new group of heroes that they are training. These new heroes could come from different backgrounds and have unique personalities. There might also be some characters from the past that have turned into antagonists due to some past grudges or misunderstandings. And of course, the Kwamis would still be there, guiding the new and old heroes alike.