In addition to the ones mentioned, Dumbledore could be a character in the fanfiction. He might try to temper Sirius's thirst for revenge and guide him towards a more just path. On the enemy side, Peter Pettigrew would be a central figure. Since he was the one who really betrayed James and framed Sirius, Sirius would likely be out for revenge against him. And Bellatrix Lestrange, as a prominent Death Eater, would also be a likely target for Sirius's revenge.
There could also be some new characters created by the fanfiction author. Maybe a young wizard or witch who becomes Sirius's apprentice of sorts in his revenge journey. They could help him with modern magic that he might not be familiar with after being in Azkaban. And on the opposing side, there could be a new and ambitious Death Eater who tries to stop Sirius from getting his revenge, adding more conflict to the story.
Obviously, Harry Potter himself is the central figure. His friends like Ron and Hermione would also be involved. They would support Harry in his revenge plans, with Ron providing his loyalty and Hermione using her intelligence to strategize. Ginny Weasley might also be part of it, as she is Harry's love interest and a strong - willed witch in her own right.
Harry Potter could be involved. He might be caught in the middle of Hermione's revenge plan on Ron. He could try to be the peacemaker, but his attempts might backfire, leading to more chaos between the two. For example, he might accidentally reveal Hermione's plans to Ron, making Hermione even more determined to succeed with her revenge.
Toriel is very likely to be involved. She has a motherly nature and would surely be concerned about Frisk's health. She would probably be at Frisk's bedside, offering comfort and warm food.
Obviously, Dumbledore himself is the central figure. Then there would be characters like Harry Potter, who might have mixed feelings about Dumbledore after learning some of his secrets. Hermione Granger could also be involved, using her logical mind to analyze the situation. And perhaps members of the wizarding government, such as the Ministry of Magic officials who might be the ones to judge Dumbledore.
Obviously Naruto himself is the main character involved. But his friends like Sasuke, Sakura, and Kakashi are also likely to be involved. Sasuke might be affected by Naruto's wishes, for example, if Naruto wishes for Sasuke to fully return to the Hidden Leaf Village and be at peace. Sakura could also be involved, perhaps in helping Naruto make his wishes come true in a medical or support way. And Kakashi, as Naruto's former teacher, would surely play a role in guiding Naruto in how to use his wishes wisely.
The other Hogwarts professors like McGonagall and Flitwick might be included. If Snape is getting revenge on students who misbehaved towards him, characters like Draco Malfoy or the Weasley twins could be part of the story. Draco might be involved if he had previously mocked Snape, and the Weasley twins could be targets if they had played pranks on Snape that he now wants to pay back.
Even some of the enemies of the Kanes could be involved in a different way. For instance, if Carter was hurt by a particular enemy, that enemy would be a central figure in the fanfiction. But there could also be unexpected allies among the enemies. Maybe a lower - ranked enemy realizes that Carter's death or continued injury could lead to a worse situation for them all, and they end up helping in some way, either by providing information about the cause of the injury or by secretly protecting Carter from their more evil comrades.
Definitely his friends from Camp Half - Blood. Percy Jackson, for instance, would be likely to be involved. He might be the one to find Nico when he's hurt or be part of the group that's trying to rescue him. Annabeth could also be involved as she is often in the thick of things and would use her strategic mind to help Nico when he's injured. Hazel, being his sister, is very likely to be there. She would be extremely worried and do whatever she can to heal or protect him.
Obviously, Harry and Ron would be highly involved. They are Hermione's closest friends. Harry would likely be the one leading the effort to find a solution, given his heroic nature. Ron, on the other hand, would probably be more involved in the day - to - day care of baby Hermione, with his big, caring heart.
Hinata would also play a major role. Since she has deep feelings for Naruto, she would be devastated by his amnesia. She might try to use their shared memories, like the time she confessed her love to him during the Pain attack, to jog his memory. And the Akatsuki members could also be involved in some cases. If Naruto's amnesia was caused by their actions, they might be the antagonists in the fanfiction, or they could also be trying to use his amnesia for their own purposes.