Some characters who have had a rough time with the Order in the past, like Sirius's old friends who were wrongly accused, could be allies. They may have a grudge against the Order and see Harry's rebellion as a chance for revenge or to right the wrongs done to them. Also, Hagrid, who has a soft spot for Harry, might secretly support him even if he doesn't openly rebel against the Order.
Hermione could be one of his allies. Despite her usually rule - following nature, she might side with Harry if she sees the merit in his rebellion. Also, Ron would likely be there, as he has always been by Harry's side through thick and thin.
Neville could be a strong ally. He has his own strength and courage, and if he believes in Harry's cause, he would join. There could also be some younger students who look up to Harry and are inspired by his rebellion. They might see the Order as old - fashioned and be eager to support Harry's new approach.
In such a fanfic, perhaps Harry might rebel because he feels the Order is being too overprotective. He could think they are holding him back from fully exploring his power to defeat Voldemort. For example, they might not let him go on certain dangerous missions he believes are crucial.
Ron could be another important ally. His loyalty and courage would be crucial. He might be the one to act as a decoy sometimes, drawing attention away from Harry when he is on a dangerous spying mission. Also, Ron's ability to blend in with the wizarding crowd could help Harry gather information without being too conspicuous.
Ron could be Harry's ally as well. Despite his sometimes clumsy nature, he's loyal and has his own areas of expertise, like wizard chess which could be metaphorically applied to some strategic decision - making in the Ministry. Additionally, some of the younger, more progressive Ministry employees who are inspired by Harry's heroics could also side with him and be his allies in any changes or projects he undertakes within the Ministry.
It could be Pikachu. Pikachu is a very popular Pokémon and it's not a legendary. It might get tired of seeing the legendaries always in the spotlight and decide to lead the rebellion. Another possibility is Charizard. Charizard is strong and has a bit of a rebellious streak already, so it would make sense for it to be involved in something like this.
Well, it could be about a group of regular Pokémon who are tired of being overshadowed by the legendary Pokémon. Maybe they start to form an alliance to demand equal treatment, like access to better habitats or more respect from trainers. They might use their unique skills in ways that the legendaries haven't expected, creating a whole new dynamic in the Pokémon world.
Daenerys Targaryen could potentially be an ally. She is open - minded about different powers and has her own dragons. Harry's magic could be seen as another powerful asset. And Jon Snow, being a noble and brave character, would likely welcome Harry's help in the fight against the White Walkers and might offer his own military expertise in return.
One possible reason could be a difference in ideology. Maybe Harry starts to question Dumbledore's decisions regarding the war against Voldemort. For example, Dumbledore's secrecy about certain things might make Harry feel left out and manipulated. Another reason could be personal pride. Harry has grown into a powerful wizard and may not want to be under Dumbledore's constant guidance and control any longer. He might think he can handle things on his own better. Also, it could be due to the influence of other characters. If some new friends or allies have different views on Dumbledore, they could sway Harry's opinion.
I think Hagrid would be a great ally. He loves all magical creatures and would be very accepting of Harry's new form as a winter spirit. He could introduce Harry to some winter - adapted magical beasts that could help him. Also, some of the older students like the Weasley twins could be allies. They would be excited about Harry's powers and use their creativity to come up with new ways to use his winter magic for fun and for the good of the school.
Another possibility is that an overzealous member of the Order who has gone too far in their methods of fighting Voldemort. Their extreme actions might make Harry think they have become as bad as the Death Eaters, so he starts to oppose them. For example, if this member starts using unethical spells on innocent people in the name of the greater good.
Hermione could be one of his allies. She's smart and resourceful, and her knowledge of magic could be very useful in different war situations. Also, Ron, with his loyalty and his own combat skills, would be a great help.