The Harry Potter novels have been around for quite some time. They started in 1997 and have become classics over the years. They've aged well and still have a huge fan base.
He may be confused at first. Fanfics can be very different from his real experiences. He might wonder why people write such things about him and his world.
Maybe it could be an ancient magical being like a centaur. Centaurs are known for their knowledge of the stars and ancient magic. They might take Harry under their wing and teach him old magic that has been passed down through their generations.
In some Harry Potter fanfics, Rhaegar might be portrayed as a mysterious figure from another realm or time. He could be a mentor - like character, using his wisdom from his own story's context to guide Harry or other characters. For example, he might share his knowledge of magic that is different from what is commonly known in the Harry Potter universe.
You can start by looking on fanfiction websites like FanFiction.net or Archive of Our Own (AO3). Just use the search terms 'Harry Potter' and 'old wizard' on their search bars, and you'll get a list of relevant fanfictions.
You can start by looking on fanfiction websites like Fanfiction.net or Archive of Our Own (AO3). Just type in 'Harry Potter old magic' in their search bars and you'll get a list of relevant fanfictions. Another way is to join 'Harry Potter' fan groups on social media platforms like Facebook or Reddit. Members often share and recommend good old magic fanfictions there.
Some characters might be in awe of the Old Gods. For example, Hermione would probably be eager to study them, their powers and their histories. Harry, on the other hand, might be more cautious, given his past experiences with powerful and mysterious entities.