Another character could be Fenrir Greyback. As a well - known and rather wild werewolf, he could be either an antagonist, trying to undermine Harry's leadership and cause chaos within the pack, or a character that Harry tries to reform. His presence would add a lot of conflict and tension to the story.
Remus Lupin would likely be a main character. Since he is a werewolf himself and has a connection to Harry, he could play an important role in the story. He might be Harry's advisor on werewolf matters, or even help him in leading the pack.
Hermione Granger could also be a main character. She might be researching ways to help the werewolves, perhaps finding new spells or potions to ease their condition. She could also be the voice of reason for Harry, helping him make decisions about leading the werewolf pack in a way that is beneficial for both the werewolves and the wizarding world at large.
Hermione would definitely be one of the main characters. She would be trying to research a way to either reverse Harry's transformation or help him control his werewolf side. Ron might also be there, at first a bit scared but then standing by Harry's side.
One possible plot could be that Harry discovers his unique ability to communicate and lead werewolves. He might use this to form an alliance between the werewolves and the wizarding world against a common enemy, like dark wizards who want to use werewolves for evil purposes.
There could be an original character created by the fanfiction author. This character might be a new werewolf in the pack, facing all sorts of challenges like coming to terms with their new identity and dealing with the discrimination from other wizards.
There could be a doll collector named Alice. She might be Harry's friend or rival, always competing to get the best dolls in the story.
Hermione could be a main character. She might be the one who helps Harry understand and control his gorgon powers. For example, she could research in the library to find ancient spells or potions that can suppress the gorgon - like effects when they are unwanted.
There might also be a love interest for Harry. This character could be someone who is also involved in the dangerous world of assassination in some way. She or he might be a fellow assassin or someone who is on the periphery of that world but still gets drawn into Harry's life, adding a romantic sub - plot to the story.
There could be the mafia boss. He might be a tough and shrewd character who takes Harry under his wing at first but later becomes suspicious of Harry's actions. Another main character could be Harry's best friend in the mafia. They go through all the dangerous and exciting adventures together, and this friend might have different views on the mafia life compared to Harry.
There could be original characters created specifically for the fanfiction. For example, a wizard who has some knowledge about the origin of the Omnitrix and tries to guide Harry. This character could be an old hermit - like wizard who has been studying interdimensional objects for years. Also, there might be a villain who is after the Omnitrix, someone who wants to use its power for evil purposes and constantly hunts Harry down.
Perhaps there's a mentor figure, an old and experienced pet trainer who gives Harry advice from time to time. Another possible character could be Harry's rival in the pet training world. This rival might always be trying to outdo Harry in training different pets, which adds some drama to the story.
There could be a range of characters. For instance, there might be a powerful Sith Lord who sees Harry as a threat to the traditional Sith ways because of his neutral stance. On the other hand, there could be a young Jedi who is initially suspicious of Harry but later comes to understand his unique position. There might also be some side characters, like smugglers or bounty hunters, who get involved in the story because of Harry's actions and the power struggle around him.