Perhaps in this fanfiction, Harry discovers a new magical ability early on that alters his destiny. For example, he could have the power to communicate with magical creatures in a way no one else can. This would lead him to form alliances with creatures like the centaurs and house - elves, which could change the course of his battles against Voldemort.
One interesting plot could be that Harry is sorted into Slytherin instead of Gryffindor. This would completely change his relationships and how others perceive him. His friendships might form with different characters, like Draco Malfoy becoming a more positive influence on him rather than an antagonist.
Perhaps the Voldemort threat in the Harry Potter world is somehow connected to a Darkness - like entity in Destiny. Harry and his friends must learn new combat techniques from the Guardians or other Destiny characters to combat this new, more powerful form of the Dark Lord. They could also exchange magical and technological knowledge, which would be really cool to see.
One idea could be to have the characters from Harry Potter interact with the Guardians from Destiny in a battle against a common dark magic - influenced enemy. For example, Harry Potter could team up with Cayde - 6 to fight off a horde of Death Eaters and Fallen that have somehow merged their powers.
Hermione Granger is often still very popular in these fanfictions. Even with an altered destiny, her intelligence and determination make her a central figure. She might be the one to figure out the implications of the changed destinies and come up with plans to deal with the new situations.
One interesting idea could be exploring an alternate destiny for Harry. Maybe he becomes a Slytherin instead of a Gryffindor. This would completely change his relationships and how the story unfolds.
One interesting concept could be the idea of a different Sorting Hat system. Maybe it sorts students based on different qualities or has a new set of houses altogether. Another could be a world where magic has different rules, like spells having unforeseen side effects that change the whole plot. For example, a simple levitation spell might make an object disappear instead.
One interesting plotline could be where Harry is sorted into Slytherin instead of Gryffindor. This would completely change his relationships within the school. He might have to deal with different prejudices and form alliances with students he would have otherwise been at odds with in the original story.
In 'Harry Potter a Different Destiny fanfiction', a possible plot twist could be that Sirius Black never dies. He could play a much larger role in Harry's life, teaching him advanced magic and helping him in ways that Dumbledore was not able to. This would change the power balance and Harry's journey significantly.
One interesting concept could be how a character's altered magical core changes their spellcasting abilities. For example, if a character's core is infused with a different type of magic, they might be able to perform spells in a unique way that others can't. Another concept could be the origin of the alteration. Was it a result of a dark curse, or perhaps an experiment gone wrong? It could also lead to new relationships and power dynamics within the wizarding world as characters with altered cores might be seen as either threats or valuable assets.
One idea could be a character who discovers a hidden power within themselves that changes their pre - determined path. For example, a character who was meant to be a simple peasant but then realizes they have magic that can make them a powerful leader. Another could be a time - travel plot where a character goes back in time to change an event that was supposed to lead to their downfall. Maybe a character was fated to die in a battle, but by changing a small decision in the past, they rewrite their entire future.
One idea could be to have the main character discover a hidden power within themselves that completely alters their destiny. For example, they might find out they can control time, and use this to prevent a great tragedy that was supposed to be part of their original fate.