Well, he might become more confident and self - assured. After all, defeating the most powerful dark wizard of all time is no small feat. He could also be a bit more somber, having seen the true horrors of the dark side up close.
Harry's character could develop a newfound sense of responsibility towards the entire magical community. He may start to see the bigger picture of how to maintain peace and harmony in the wizarding world. Instead of just reacting to Voldemort's threats, he becomes proactive in making changes. For example, he could work towards reforming the Hogwarts curriculum to include more in - depth studies of dark magic and how to combat it, so that future generations are better prepared. He also might become more empathetic towards former Death Eaters who are trying to reform, as he realizes that many of them were influenced by Voldemort's power and fear.
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.
The wizarding world would likely be in a state of shock and then celebration. People would start to see Azkaban in a new light, perhaps no longer as just a place of horror but also as the site where the great evil was finally vanquished.
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.
Yes, there might be such fanfictions out there. Fanfiction writers often explore alternative storylines, and the idea of Pettigrew turning on Voldemort and killing him is an interesting and unexpected twist. It could involve Pettigrew having a change of heart due to some complex reasons, like realizing the true evil of Voldemort's ways or having a personal vendetta against him that overrides his loyalty.
His character development would be extremely different. He would no longer be the 'chosen one' in the traditional sense. He might feel a sense of shame or guilt that he didn't have before. His self - confidence would take a huge hit. He would constantly be looking over his shoulder, wondering if people were judging him based on his father. His magic might also change. He could have an easier time with some of the more complex and darker spells, but at the same time, he would have to be extra careful not to let that power corrupt him. His moral compass would be all over the place as he tries to reconcile the fact that he is the son of the most evil wizard with his own desire to be a good person.
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.
He'd be more confident. With a loving mother around, he wouldn't have the insecurities that came from growing up with the Dursleys.
Harry might be more self - assured. Charlus, being from an older time, could have a more no - nonsense approach to teaching Harry magic. This would make Harry more confident in his abilities. For example, he might not second - guess himself as much as he does in the original story.
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.