Harry's character could develop a different sense of loyalty. In his original life, he was loyal to his friends mainly because they were his support system. But as James' brother, he would have an in - built loyalty to the Marauders. This could make him more protective of them and might lead to him making different decisions when it comes to their safety and well - being.
He might be more confident from the start. In his past life, Harry grew up without his parents and had a difficult childhood. But as James' brother, he would grow up in a loving family environment. This could make him more outgoing and less hesitant in social situations.
Harry's character would develop with a stronger sense of family pride. He'd be part of the Potter family in a different way than before. He would grow up with a different set of values, influenced by James and his parents. He could be more adventurous, knowing that he has a support system. Also, his understanding of the wizarding world would be more in - depth from the start. He might not be as naive as he was in his original life when it comes to the darker aspects of the wizarding world, because he already has the knowledge of what can go wrong.
He'd likely be more inquisitive about different forms of magic. Instead of just relying on the spells taught at Hogwarts, he'd constantly seek out new magus - based knowledge.
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.
He'd be more confident. With a loving mother around, he wouldn't have the insecurities that came from growing up with the Dursleys.
His magical abilities might develop in a different way. The Malfoys could introduce him to different types of magic or magical artifacts. Maybe he'd learn more about the Dark Arts in a different context, not for evil purposes but just to understand it better. He could also become more skilled in areas like Occlumency earlier on, since the Malfoys might see it as an important skill to protect their family secrets. His relationship with his Gryffindor traits would be tested. He might still have his bravery, but it could be expressed in different ways, like standing up to the Malfoy family's wrongdoings.
Harry would be more confident in his physical abilities. Since Raiden is a powerful fighter, he'd train Harry to be strong and fearless in combat. This would be different from the Harry we know who often relied on his wits and magic in dangerous situations. Harry might also be more stoic, like Raiden, and not show his emotions as easily.
Harry would be more daring. Jack Sparrow's influence would make him less afraid of taking risks. In the wizarding world, this could mean he'd be quicker to explore dark and dangerous places. He might not wait for permission or for a group to support him, but rather just dive in like Jack does when facing a new situation on the sea.
Harry's character would develop a sense of divinity within him. Since he's raised by Greek gods, he'd have a different relationship with power. He wouldn't fear power as much as he might in the original story. Instead, he'd see it as a natural part of his being. He'd be more in tune with nature and the elements, like the gods are. His relationships with other characters would also change. He might be more aloof towards some of his Hogwarts friends at first, as he'd have this whole other world of experiences from his upbringing among the gods that they couldn't understand right away.
He'd be more confident. With Sally's love and support, he wouldn't have the self - doubt that he had in the original story. He'd be quicker to trust people and might be more open - minded about different forms of magic.
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.