Well, the main character is Harry Potter. In these fanfictions, he is often given the title 'Lightning Lord' which implies that he has some sort of special connection or power related to lightning. This new aspect of his character then drives the plot in different and often exciting directions compared to the original Harry Potter series.
The main character in 'Lightning Lord Harry Potter' fanfiction is Harry Potter, of course. But in these stories, he is a different kind of Harry. He has the added dimension of being the 'Lightning Lord'. This could mean that he has unique magical abilities that are centered around lightning. These abilities might attract different types of characters to him, both good and bad. Some might see him as a great hope for the wizarding world, while others might view him as a threat to the existing power structures. All these elements combined make for a very interesting take on the character of Harry Potter in fanfiction.
Obviously, Harry Potter would be one of the main characters. He would be the one most likely to interact with the concept of the 'Lord of Lightning'.
Obviously, the Lightning Lord is a main character. There could also be the classic Harry Potter characters like Dumbledore who might play a role in the story. They could be either guiding the Lightning Lord or trying to figure out their intentions.
It could be a new student at Hogwarts who has the powers of a Lightning Devil Slayer. This character would be an outcast at first, not fitting in with the normal wizarding students. But as the story progresses, they use their unique abilities to save the day, for example, during a battle against a horde of Dementors where their lightning - based powers are especially effective.
It's hard to say for sure without reading it, but it's likely that Harry Potter himself would be one of the main characters, as it's in the title. Hermione and Ron could also be involved since they are Harry's closest friends in the original series.
Most likely, Harry Potter remains the main character. After all, it's a 'Harry Potter' fanfic. He would be the one to take on the challenges presented by the Nightmare Lord.
Maybe it's a well - known character like Hermione. Given her intelligence and leadership skills, she could be thrust into a situation where she becomes the lord of many houses. She would then use her knowledge of magic and her ability to make friends across different groups to manage the houses effectively.
Another possibility is a dark wizard who has been secretly studying the power of the God of Lightning for years. This wizard wants the power all for himself and sees Harry as an obstacle. He could be a former Death Eater who has broken away from Voldemort's group to pursue this power on his own. He would use his knowledge of dark magic and his own minions to try and take the power from Harry.
Dumbledore can also be a main character in such fanfictions. He might have known more about the Lightning Bolt scar than he let on in the original series. Fanfiction could explore his past interactions with Harry's parents regarding the scar and how he was secretly guiding Harry towards unlocking the full potential of the Lightning Bolt.
There could be a group of characters. It might include some well - known Harry Potter characters like Hermione and Ron, but with a new twist. For example, they could be mentoring a new generation of wizards, and one of those new wizards has a special ability that is symbolized by the lightning bolt. So they all get involved in a story centered around this new ability.
The main character is obviously the Lightning Dragon Slayer. But there could also be appearances from well - known Harry Potter characters like Harry, Hermione, and Ron. They might interact with the slayer in various ways, either as allies or with some initial suspicion.