Perhaps Harry's time on the streets leads him to befriend a powerful but misunderstood magical creature that is feared by most wizards. This creature becomes his loyal companion and helps him in ways no human could. For example, it could have the ability to sense dark magic from afar, allowing Harry to be better prepared for Voldemort's attacks.
One interesting plot twist could be that they discover a hidden magic that binds their fates together from a very young age. This magic makes them able to sense each other's emotions and they have to learn to deal with this new connection while still being in the rival houses at Hogwarts.
One plot idea could be that as Harry grows up clever, he quickly masters advanced magic spells much earlier than in the original story. For example, he might learn Patronus charm in his third year and use it to protect his friends in a more creative way, like using it to send messages through the form of his Patronus.
The 'Harry Potter Prince of the Streets' fanfiction might tell a story where Harry Potter discovers a whole new side of the wizarding world that is not often explored in the original books. He could be like a prince in the sense that he has a certain charisma and power that draws people to him. It could involve him forming alliances with street - smart characters, like perhaps some young wizards who have grown up in the slums of Diagon Alley. Together, they might be on a mission to clean up the streets from dark magic and corruption, and Harry's unique skills and experiences at Hogwarts would play a crucial role in this adventure.
One interesting plot twist could be that Harry discovers he has the ability to communicate with the Basilisk on a deeper level than just Parseltongue. Maybe he can see through the Basilisk's eyes and use this to his advantage in uncovering secrets within Hogwarts that even Dumbledore doesn't know. Another could be that the Basilisk is not truly a villain but was being controlled by a dark force all along, and Harry has to find a way to break that control and free the Basilisk.
One interesting plot twist could be that the basilisk has an unexpected alliance. Maybe it teams up with a group of outcast magical creatures to take revenge on those who have wronged them. This would completely change the dynamic as in the original, the basilisk is mainly a tool of Voldemort.
In this fanfiction, a great plot twist might be that the gamer's knowledge of game strategies is used to outwit Voldemort in a completely unexpected way. Instead of a traditional magical duel, the gamer uses their understanding of leveling up and collecting power - ups to somehow weaken Voldemort's magic. Maybe they find a way to 'hack' into his dark magic, using skills from the game world that no one in the wizarding world had thought of before.
Well, in some 'Harry Potter and the Prophecy' fanfiction, a plot twist could be that the prophecy was not a prophecy at all but a spell cast by an ancient wizard to set in motion a series of events for a greater purpose. For example, it was to bring about a new era of magic where Muggle - borns and pure - bloods could co - exist peacefully. This would completely change the way the characters view the prophecy and their roles in it. Also, the prophecy might be tied to a different character than Harry or Voldemort, like a minor character who suddenly becomes central to the whole story.
One interesting plot twist could be that instead of Ron leaving and coming back, Hermione actually leaves the group for a while because she discovers a dark secret about her family's past that she needs to figure out on her own. This would add a whole new layer of drama to the story.
One interesting plot twist could be that Harry Potter was actually in a magically induced coma rather than dead. He wakes up with new powers and a deeper understanding of magic. This could lead to him having to relearn how to interact with the wizarding world he thought he left behind.
One interesting plot twist could be that Kami's magic is so different from the wizarding world's that Harry develops entirely new spells. For example, he might be able to use nature - based magic in ways wizards never thought of. Another could be that Kami's values of honor and purity influence Harry to take a different stance on the fight against Voldemort, perhaps trying to redeem him first. Also, the magical creatures in Kami's world could interact with the ones in Harry's world in unexpected ways, like a friendly competition between a hippogriff and a kirin.