His character might be more distrustful. Since his parents left him, he may have a hard time trusting others, especially authority figures like Dumbledore. He could be more independent too, having to fend for himself from a young age. For example, he might not be as quick to accept help from others at Hogwarts.
Often, it starts with Harry realizing the full extent of being left by his parents. This could be through a memory or an encounter. Then, he may go through a period of sadness and confusion. For example, in some fanfictions, he might struggle with his self - worth.
Harry would likely be more cynical. Without the love and support of his parents, he'd grow up feeling abandoned. He might be more distrustful of others, especially those who claim to be helping him. For example, he might not trust Dumbledore as easily as in the original story.
He would be more confident. Without the trauma of losing his parents, Harry would not have that underlying sense of insecurity. He would probably be more outgoing and less hesitant in making friends and taking risks.
Harry's character would develop in a more patient and self - assured way. Merlin's long - lived experience and his different approach to magic would shape Harry. Instead of the somewhat isolated and often confused boy in the original story, he would be more open - minded. He would be exposed to different magical cultures and ideas from Merlin, which would make him a more well - rounded wizard. He would also be more in tune with the ancient and hidden parts of magic, and this would give him a different kind of power and presence.
Harry would likely become more feared by some in the wizarding world. Since the Basilisk is often seen as a terrifying and dangerous creature, his connection to it might make others view him with suspicion. He would also have to grapple with the darker side of magic that the Basilisk represents, which could make him more brooding and introspective.
Naruto would be more self - assured. In the original, he was always seeking approval because he was an orphan. With his parents alive, he'd have that unconditional love and support, so he wouldn't be as desperate for others' recognition.
Harry would be more open to dark magic. Since Voldemort is his adoptive father, he would be exposed to different aspects of magic earlier. He might not have the same fear of the dark side as in the original story. For example, he could be more confident in using spells that are considered dark but for good reasons, like using the Imperius Curse to stop a criminal.
He develops a more rebellious streak. In the original, Harry was quite respectful of authority in the wizarding world. But being raised by bikers, he might question rules more often. For example, he might not be as quick to follow Hogwarts' strict regulations.
Harry becomes more empathetic. Usually, he and Snape have a rocky relationship. But when he saves Snape, he starts to see Snape in a new light. He realizes that Snape is more complex than he thought, which makes him more understanding of others' hidden motives and pain.
Harry could be more independent and self - reliant. Growing up with a Pegasus rather than in a human family means he has to rely on himself and his Pegasus friend more. He would learn to fend for himself at a younger age, which would make him bolder in the face of danger.