Obviously, Harry Potter himself is the central character as he's the one getting the wish. Hermione and Ron are also commonly involved. They are Harry's best friends, so they would be there to support him or perhaps even influence his wish. Dumbledore also often shows up in these fanfictions. As the wise headmaster, he might guide Harry on how to use his wish wisely or warn him of the consequences.
Obviously, Harry Potter himself is the central character. His friends like Ron Weasley and Hermione Granger are also often involved. They might try to visit him while he's grounded or come up with plans to get him out of being grounded. Dumbledore could also play a role, either as the one who enforces the grounding in some cases or as the one who might offer some wisdom to Harry during his time of confinement.
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.
Hermione Granger is also a common character. Given her love for knowledge and her skills in magic, she would likely be researching the best spells and magical theories to make the terraforming successful. She might be the one to find ancient spells that are crucial for the process.
In many expelled Harry Potter fanfictions, the Weasley family as a whole gets involved. Molly Weasley would be worried sick about Harry and would be cooking up plans to get him back. Fred and George might use their prank - making skills to expose the truth behind the expulsion. Ginny, being Harry's love interest in the original series, would be actively involved in trying to clear his name. And don't forget about the Hogwarts professors. McGonagall would probably be torn between following the rules and believing in Harry.
Harry Potter himself is often a central character. He might be shopping for new school supplies at Flourish and Blotts or looking for a new broomstick at Quality Quidditch Supplies. His friends, like Hermione and Ron, usually accompany him. Hermione might be more interested in books and rare magical artifacts, while Ron would be eyeing the latest Quidditch gear.
Mrs. Weasley is a very likely character. She's an expert at cooking and baking in the normal wizarding world, so in fanfiction about magical bakes, she could be teaching the younger characters how to make special bakes. Hagrid might also be involved. He could bring in some really strange ingredients from the Forbidden Forest, like giant acorns, to be used in the bakes.
Hermione Granger is often involved. In some fanfictions, she discovers hidden conspiracies within the Hogwarts library. For example, she might find a book that reveals a plot by some of the older pure - blood families to keep certain magical knowledge from half - bloods and Muggle - borns.
Obviously, Harry Potter himself would be the central character. He's the one getting the tattoos after all.
Dumbledore can also be a significant character. He might be the one who decides Harry's punishment or he could be the one to offer some wisdom to Harry during his time of being grounded. And of course, the teachers like Snape or McGonagall could be involved as they are often the ones who enforce the rules and punishments at Hogwarts.
The villains in the Harry Potter series, such as Voldemort or his Death Eaters, could also play important roles. Harry's anger might be directly related to their actions. For instance, if Voldemort were to target someone Harry cares about again, it could be the trigger for his extreme anger. His interactions with these villains in the fanfiction would be full of tension and high - stakes confrontations.