It could be Athena. She is known for her wisdom, and Harry has shown great intelligence throughout the series. Maybe his strategic thinking and ability to solve complex problems come from his connection to Athena.
The plot might involve Harry being drawn into the world of Greek gods and goddesses. He could be on a quest to find out more about his mother, the Greek goddess. Along the way, he might meet other demigods or creatures from Greek mythology. His Hogwarts friends could be either helping him or being a bit confused by this new side of Harry. And he'd probably have to balance his life at Hogwarts with his new adventures in the Greek mythological realm.
No. Harry Potter is a series of novels about a young wizard named Harry Potter in a magical world of its own, not related to Greek goddess fanfiction at all.
Hera could be an interesting option. As the queen of the gods, she has a strong and commanding presence. If she were to interact with Naruto, it could be a story of power struggles and mutual respect. She might see Naruto as a potential ally or threat, and the fanfiction could explore how their relationship develops over time.
The goddess could also be an original creation for the fanfiction. A being with a unique set of powers like the ability to control time and space. This goddess could be betrothed to Harry to stop an impending doom that threatens both the wizarding and Muggle worlds. Her powers would be so great that she needs Harry's connection to the wizarding world to fully utilize them and save the day.
It could be Athena. Athena is known for her wisdom in Greek mythology. She could pass on her wisdom to Harry, making him not just a powerful wizard but also a very wise one. He could use this wisdom to solve problems in the wizarding world in a more strategic way.
The goddess could be an ancient Celtic deity. In the fanfiction, the author might choose a Celtic goddess because of the rich magical lore associated with them. For example, Morgan le Fay from Arthurian legend could be reimagined as a goddess in this context, and she could adopt Harry due to her interest in powerful magic users.
She could be an ancient Celtic goddess, like Brigid. Brigid is associated with magic, healing, and smithcraft in Celtic mythology. In the fanfiction, she might see Harry's potential and decide to train him in her unique magical arts.