Papyrus could be involved. He might be trying to convince Undyne to find a peaceful solution or he could be on her side and help in the war effort in his own way.
Alphys might also be a part of it. She could be in charge of creating weapons or technology for Undyne's side. Or she might be worried about the moral implications of the war and try to stop it from behind the scenes.
In this fanfiction, it could be that Undyne declares war against an unjust regime. She might gather an army of like - minded individuals and engage in battles that not only test her physical strength but also her strategic thinking. The story could detail her training of troops, her alliances, and the challenges she faces on the battlefield.
She is also very determined. This trait can make for an interesting dynamic in the fanfiction. If the reader is facing a difficult task, Undyne's determination can inspire them. She won't give up easily, and that attitude can rub off on the reader and help them grow as a character.
Well, Ron is a given. He's Hermione's significant other, so he'd be deeply involved in the whole process. Luna Lovegood might also make an appearance. She has an unique perspective and could bring some calmness and different kind of support. And don't forget about Hagrid. He has a big heart and might come to offer his congratulations and well - wishes in his own, endearing way.
Other characters like Ginny Weasley could be part of 'hermione fails' fanfiction. Ginny might be Hermione's confidante when she fails in a relationship, offering advice based on her own experiences. Neville Longbottom could also be involved. He could be in a situation where Hermione fails to recognize his potential or she fails to help him when he needs it most. And of course, the Weasley twins, Fred and George, could be involved. They might use Hermione's failure as inspiration for one of their pranks or they could be the ones to cheer her up in a humorous way after she fails something important.
Some of the older students like the Gryffindor prefects could support Harry. They understand the importance of a just Hogwarts environment. Neville Longbottom could also be a strong supporter. He has grown a lot in courage throughout the series, and this would be his chance to show his loyalty to Harry and fight against Umbridge's unfair treatment of the students.
Harry Potter is a very likely character. Given his often - tense relationship with Snape, detention with Snape could be a great opportunity to explore their dynamic further. Harry might learn more about Snape's motives during these detentions, or they could have some unexpected conversations that change Harry's perception of Snape.
Sasuke could be involved. Since they have a complex relationship, Sasuke might either be a rival during Naruto's training, pushing him to be better, or he could end up joining Naruto in some training sessions to become stronger together.
Definitely Ash, as he's the center of Serena's affections. But also, there could be new female characters created specifically for the fanfiction. These new characters might be trainers who are really good at Pokemon battles and catch Ash's attention. Serena would then become jealous of their skills and the attention Ash gives them. Additionally, any of Ash's Pokemon that seem to have a special connection with another character could also be part of the scenario that makes Serena jealous. For example, if Pikachu seems to like a new girl more than Serena, that could be a reason for her jealousy.
Magnus Bane could be involved. He has knowledge of both the magical and vampire worlds, so he could offer advice or help. Clary Fray might also be there, as Isabelle's friend, she would be supportive during the pregnancy. And of course, Simon, who has his own connections to the vampire world through Raphael.
The Lone Wanderer is likely to be involved. They have a pre - existing relationship with Amata from the game. Her father, the Overseer, might also play a role, either in supporting or opposing the situation. Other characters from Megaton or Tenpenny Tower could potentially be involved as well.