Since it's a fanfiction, the author might choose to focus on some of the minor characters from the original series and give them a more prominent role in the context of the 'gods' storyline. For example, Neville could be a key figure if he discovers a connection to a god related to plants or nature, and his new - found power and role in the story could be a central part of the fanfiction.
It's hard to say for sure without reading it, but it could be that Harry, Hermione, and Ron still play major roles. They might be interacting with the gods in some way, either seeking their help or being caught in the middle of a conflict involving the gods.
The main character is Harry Potter without a doubt. However, there could be a whole host of other characters. We might see Dumbledore or other Hogwarts professors making an appearance, trying to understand or guide Harry in this new situation. And then there are the god - characters. They could range from powerful and benevolent deities who want Harry to succeed in his new role as champion, to more malevolent ones who see him as a threat or a tool for their own ends. There could also be new characters created specifically for this fanfiction, like other champions from different magical communities who are also vying for the title or recognition from the gods.
It could be Zeus. He is a powerful god and might see Harry as a worthy candidate for training. He could teach Harry about leadership and power control.
Zeus could be one. He is a powerful god in Greek mythology and might be interested in Harry's story. Another could be Odin from Norse mythology, known for his wisdom. And perhaps Isis from Egyptian mythology, as she has powers related to magic and protection.
Obviously, Harry Potter would be the main character. He would be the one with the new role as the master of the Nordic gods. Hermione and Ron could also be involved. Hermione would be very interested in learning about the Nordic magic and gods, and Ron might be there to provide some comic relief and also be a loyal friend in the new adventures.
The four gods in this fanfiction could be created to fit the unique world of Harry Potter. They might be named after something related to the wizarding world, like one could be the God of Magic Wands, another the God of Potions, etc. However, this is just speculation. It really depends on the creativity of the fanfiction writer. They could also be based on the four elements, with each god having control over one element, like fire, water, earth, and air, and these elements play a crucial role in the magic of the Harry Potter universe as described in the fanfiction.
The Chaos Gods themselves could be the main antagonists. Their very nature is to create chaos and disorder, which would be directly opposed to the order and stability that Hogwarts and the wizarding world try to maintain.
There could be new characters created specifically for this fanfiction that are central to the merging concept. For example, a character who has the ability to control the merged magic or someone who is the key to uniting different groups of wizards that were brought together in this fan - made story.
Ron Weasley might be another main character. His loyalty to his friends and his sometimes comical, yet brave nature could be important in a story centered around a boomslang. There could also be new characters introduced in the fanfiction that are specifically related to the boomslang, like a character who is an expert on boomslangs or has a special connection to them.
Often, the main characters are still Harry, Hermione, and Ron. But with the addition of the nanites, their personalities and abilities might change. For instance, Harry could use the nanites to better understand Voldemort's magic.
Well, Harry Potter would most likely still be a main character. His journey of growth and how he adapts to the evolving world around him would be a central focus.