Besides Harry, Draco Malfoy could be a key character. He has his own complex journey and could be either an adversary or an unexpected ally in Harry's struggle to salvation. Snape might also be present, either through memories or some form of spectral guidance. His actions in the original series were full of mystery and his influence could still be felt. And Hagrid, with his big heart and connection to the magical creatures, could be involved in helping Harry in his journey, perhaps providing some form of natural or creature - based solution to the problems Harry is facing.
Well, Ginny is very likely to be involved. She's Harry's love interest and would support him through his struggles. Neville could also play an important role. He has grown into a strong and brave wizard, and could be a valuable ally for Harry. Luna might be in it as well. Her unique perspective on magic and the world could provide Harry with new insights as he tries to find salvation. And of course, the Weasley family as a whole would probably be involved in some way, given their close relationship with Harry.
Hermione would definitely be involved. She's always been by Harry's side, and in this kind of fanfic, she would likely be helping Harry in his struggle, using her intelligence to figure out solutions to the problems he faces. Ron would also be there, providing his loyalty and courage in the fight. Dumbledore might make an appearance too, perhaps as a guiding spirit or in flashbacks, offering his wisdom to Harry as he battles towards salvation.
Hermione would probably be involved. She's always by Harry's side, and she might be researching ways to help Harry tame the basilisk. Maybe she finds some useful spells or information in the library that gives Harry an edge.
Obviously, the illithid would be a main character. It could be a mysterious and powerful being that Harry encounters. Also, Hermione and Ron might still be important characters. They could be either suspicious of the illithid or try to help Harry understand it better. Dumbledore might also play a role, perhaps guiding Harry in his interactions with this strange new creature.
Definitely the Weasley family. Molly and Arthur Weasley would be very much involved. Molly would be all excited about the wedding preparations, fussing over Ginny's dress and the food for the reception. Arthur would be there to offer his support and probably share some interesting wizarding stories. Ron and Hermione would also be there. Ron as Harry's best friend would be part of the pre - wedding jitters and celebrations. Hermione would be helping Ginny with all the details, like choosing the right flowers and making sure the wedding venue is decorated perfectly.
Snape could also be part of it. He might catch Harry in a rather awkward moment when he's trying to hold it in and give him a hard time. Or, on the other hand, he could surprisingly offer some help in a very Snape - like way.
Hermione could be involved. She might suspect Daphne of having ulterior motives regarding Harry and try to warn him, which could play into the betrayal storyline in some way, either as a catalyst or as someone who helps Harry deal with the betrayal later.
Hermione is a must. Her intelligence and extensive knowledge of magic and Hogwarts rules would be invaluable. Ron would be involved too. He's Harry's close friend and has a bit of a mischievous streak himself. Fred and George Weasley are very likely to be part of it. They are known for their love of pranks and their dislike of authority figures like Umbridge. Luna Lovegood could also be included. She has a unique perspective and might come up with some really out - of - the - box ideas for Harry's revenge on Umbridge. Plus, her presence would add an interesting and somewhat dreamy element to the whole revenge plot.
Well, Hagrid would be a great addition. He could bring in some friendly magical creatures for the preschoolers to see, like baby owls or small unicorns. The kids would be thrilled to meet them.
The Weasley twins could be part of it too. Suppose Harry yells in excitement or anger about a new prank idea that the twins have come up with that might be a bit too dangerous. They could either encourage his yelling or try to tone it down, depending on their mood. And Malfoy might overhear Harry's yell and use it as an opportunity to taunt him, adding more conflict to the fanfiction.
Definitely Hermione and Ron. Hermione would use her intelligence to analyze the situation and come up with a plan. Ron would be the more impulsive one, ready to jump into action. Sirius Black could also be involved. Since he has a history with Pettigrew, he might have some insights into Pettigrew's actions and be able to help in the search for Harry. Also, the Weasley family in general might get involved as they are close to Harry.
Obviously, Harry Potter himself would be a main character. Since it's about a betrothal contract related to him. And probably the person he is betrothed to, whoever that may be in the fanfic's universe.