His best friend Clyde could be a main character. Clyde might have had braces before and can share his own experiences with Lincoln. He could be the one who encourages Lincoln when he's feeling down about his braces and helps him see the positive side of having them.
His parents could be main characters too. They might be the ones who take Lincoln to get his braces in the first place. And they could be there to support him throughout the process, like when he's having trouble eating because of the braces pain, they make him special soft foods.
His sisters could be main characters. For instance, Lori might give him some advice on how to deal with the braces since she's the eldest and has more experience. Or Leni could be there to offer some fashion tips to make him feel better about his new look with the braces.
Perhaps the fanfiction focuses on how Lincoln gets braces and it changes his appearance. His crush could either like the new look or be put off by it at first. He then has to deal with his feelings of insecurity while also trying to show that he's still the same Lincoln, braces or not. For example, he might still be the one to come up with great plans for family outings or helping his siblings with their problems.
The shooter could be a main character. We could explore their motives, their background, and what led them to commit such a heinous act. For example, if the shooter was a disgruntled former soldier who felt Lincoln had wronged him in some way. Another character could be Lincoln's wife. We could see her reaction, her grief, and how she copes with the situation. Or perhaps a doctor who tries desperately to save Lincoln's life could be a main character, showing the medical challenges and the hope against all odds.
Well, his sisters from 'The Loud House' could make an appearance in some way. Maybe they get transported to the Pokemon world too, or they are just part of Lincoln's memories that he draws strength from. In the Pokemon world, he could meet classic Pokemon characters like Ash, Misty, and Brock. They could help him on his journey or be rivals in some Pokemon battles.
There might also be some original characters created specifically for the fanfiction. These could be other humans who know about Lincoln's secret or other supernatural beings that are related to the vampire lore in the story.
Maybe some new kids in the neighborhood who are trying to establish their dominance and pick on Lincoln as an easy target. They might not know much about him or his family, but just see him as someone they can bully.
His siblings could be responsible. They are always getting into crazy situations together, and maybe one of their pranks or games goes too far and accidentally hurts Lincoln.
Well, of course, Lincoln Loud would be one of the main characters. He's the central figure in the Loud family, so it makes sense for him to be the focus in this fanfiction. His sisters might also be involved. For example, Lola could be competing with Lincoln in a lemon - themed beauty pageant, adding some sibling rivalry to the story.
Hermione would definitely be one of the main characters. She could be the one to research all about braces in the wizarding library to see if there are any magical implications or ways to make the process easier for Harry. And she would offer him lots of advice and support.
Maybe it could be about Lincoln getting into a fight with some bullies at school who beat him up because he stands up for someone. Then his family might find out and there's a whole drama about dealing with the bullies and helping Lincoln recover.
Maybe it's a new villain in Royal Woods. This person could be jealous of Lincoln's leadership skills within his friend group. So, they kidnap him to try and undermine his confidence and make his friends turn against him. They believe that without Lincoln, the group will fall apart and they can take over as the new 'leader' in the neighborhood.