Well, Hawkmoth might become more powerful. Maybe the villain guide teaches him new ways to manipulate people or use his powers more effectively.
Perhaps the villain guide helps Hawkmoth understand his own motives better. He could start to question his actions and goals, which might lead to a change in his plans. On the other hand, the guide could also push him to be more ruthless, causing even more chaos in the story.
It could be an unknown villain from another dimension. Somebody with a lot of knowledge about dark magic and villainy.
It could be a character from a different dimension or realm. This character might have some sort of connection to the Miraculouses and sees potential in Hawkmoth. They decide to help him, thinking that they can redirect his actions towards a more positive outcome, or at least a less destructive one.
I'm not sure specifically as I haven't read this particular fanfiction. But the guide could be someone with special powers or knowledge. Maybe Hawkmoth gets help like strategic advice or some form of magical assistance to further his evil plans.
Hawkmoth's character development in the 'hawkmoth gets help from a guied fanfiction' could vary. Initially, he's all about his evil plans. But with the guide's help, he could become more empathetic. For instance, the guide might show him the consequences of his actions on the people of Paris. This could make him hesitate in his villainous deeds. He may also start to adapt new skills or knowledge from the guide, which could change his modus operandi. This new influence could make him a more three - dimensional character, with a mix of his original villainous traits and some new elements introduced by the guide.
Well, in some fanfictions, Hawkmoth might use false promises. He could promise Cat Noir something like the power to save a loved one in exchange for his help.
Maybe the guide is a time - traveler. Someone from the future who has seen the consequences of Gabriel's actions and comes back to try and change the course of events. This time - traveler would know all the ins and outs of what's going to happen and could guide Gabriel towards making better choices. They could show him the destruction his actions as Hawk Moth will cause and offer him an alternative path to achieve his goals in a more positive way.
One consequence could be that he loses his standing as a hero in Paris. People who once looked up to him would see him as a traitor.
One possible plot could be that Gabriel Agreste, in his search for a way to achieve his goals (maybe related to his fashion empire or his secret identity as Hawk Moth), gets help from an unexpected guide. This guide might be a character who has unique knowledge of the Miraculous or the hidden aspects of Paris. For example, the guide could be an old acquaintance who has connections to the magic that surrounds the Miraculous. They might lead Gabriel to discover new powers or secrets that could change his approach to his plans.
If Adrien becomes Hawkmoth in fanfiction, Paris would be in for a major shock. His friends, like Nino and Alya, would never suspect him at first. And Marinette, who is Ladybug, would be facing a completely different kind of enemy. She's used to fighting Hawkmoth as this unknown figure, but now it's someone she knows so well. It would change the dynamic of their battles entirely.
If Harry Potter gets help from the Queen in fanfiction, the Queen could offer her strategic wisdom. Given her experience in ruling and dealing with various threats, she could help Harry plan his battles against Voldemort. She might also introduce Harry to a network of powerful Muggles who could support his cause in different ways, like providing financial aid for the Order of the Phoenix or helping to spread anti - Voldemort propaganda among Muggles.