Hermione would definitely be one of his allies. She is smart and would be able to help him research about his new identity and how to control his powers. For example, she could find ancient texts in the Hogwarts library that relate to both the wizarding world and the Greek gods.
Ron could also be an ally. Despite his initial confusion or jealousy, he would come around because of their long - standing friendship. He could be useful in providing moral support and also in practical ways, like helping Harry keep his new identity a secret from those who might want to use it against him.
His friends from Hogwarts could still be his allies. Hermione would use her intelligence to help him understand his new situation. Ron would be there for moral support. Additionally, any friends or allies that Rias has in her world could also become Harry's allies. They might be magical creatures or other powerful mages.
Hermione would definitely be an ally. She's smart and would be able to help Harry research about his 'son of Mars' heritage, finding ancient spells or texts that could explain it further.
In this fanfiction, some of the potential allies for Harry could be the magical creatures that have a connection to Norse mythology. For example, the Valkyries. They could help Harry in battles or in understanding his new heritage. Another ally could be Odin, Frigga's husband. Despite the initial shock of Harry's existence, he might see the value in Harry and offer his protection and guidance. And don't forget Neville. He's always been a loyal friend to Harry, and in this new scenario, he would continue to be an ally, perhaps even more important as Harry faces new and different challenges.
One potential ally could be Hagrid. Hagrid has always been a friend to Harry, and in this fanfiction, he could help Harry understand his newfound heritage as the son of Hephaestus. Hagrid's knowledge of magical creatures could also be useful in Harry's adventures related to his Hephaestus - given abilities.
Dumbledore could be a powerful ally. He has a deep understanding of magic and would be interested in exploring Harry's new abilities. Also, some of the more open - minded members of the Order of the Phoenix might see the potential in Harry's unique heritage and support him, like Lupin or Sirius if they were still alive in the fanfiction.
In the fanfiction, Harry might find allies among the ghosts in Hogwarts. Since he is the son of Hades, he could have a special connection with them. They could provide him with information and support. Another potential group of allies could be the outcasts in the wizarding world. People who have been shunned or misunderstood might be drawn to Harry because they see him as a fellow outcast due to his new identity. And there's also a possibility that some of the more rebellious students at Hogwarts, who are not afraid to go against the norm, would become his allies and help him face the challenges that come with being the son of Hades.
There could be some characters from outside the North as well. For example, a wandering knight who is impressed by Harry's courage and Stark - like qualities. Or perhaps a foreign noble who has heard of the Starks' reputation and sees Harry as a means to gain influence in the Westeros. These unexpected allies could bring new perspectives and resources to Harry's cause.
There could be. The world of fanfiction is vast and full of creative and wild ideas. Since both Harry Potter and the concept of Poseidon are well - known in their respective fictional realms, it's not surprising that someone might come up with a story where Harry Potter is Poseidon's son. It allows for new storylines, new powers for Harry, and a whole new take on the familiar Harry Potter story.
Some potential new allies could be the house - elves. They might see Harry's plight and decide to help him, using their unique magic and knowledge of Hogwarts' secrets. Another could be the centaurs in the Forbidden Forest. They are very wise and may take Harry under their wing.
His allies could include Hermione and Ron as always. Since they are his best friends, they would support him in his apprenticeship. Hermione might even help him study and research with Flitwick. Neville could also be an ally as he is also interested in learning more magic. As for rivals, Draco might be jealous of Harry's new position and try to undermine him. Some of the Slytherins who don't like Harry might also be his rivals in this scenario.