One possible plot twist could be that the goblins have their own motives for raising Harry. Maybe they see him as a key to some hidden treasure or power. They could be training him in secret goblin magic that no human wizard knows about.
Well, perhaps the story could involve Harry learning the goblin ways of magic and combat. He might grow up with a unique perspective on the wizarding world, seeing things from the goblins' point of view. Maybe he'd have a special bond with goblin characters and use their knowledge to outwit his enemies later in life.
Perhaps a plot twist could be that the magical creatures interact with Harry differently. In the original, they had a certain way of relating to him, but in this fanfiction, being raised as a black wizard might make some creatures more or less friendly towards him. Some might see him as a symbol of change in the wizarding world and be more drawn to him, while others might be suspicious. Also, the way Harry approaches magic could be different. He might draw on cultural magic that is unique to his black heritage, which could give him an edge in certain situations or make him a target for those who fear change.
Maybe Harry would have a different view on the wizarding world. Growing up with the Delacours, he'd be exposed to a more international magical community from a young age. So, instead of being so focused on the British wizarding world's problems like Voldemort, he might be more interested in international magical relations and how to unite different magical cultures.
Well, one possibility could be that Harry grows up with a very different set of values. Goblins are known for their love of gold and their shrewdness in business. So Harry might be extremely good at handling finances and valuing things in terms of their worth. He could also have a more aggressive and territorial nature, like the goblins. For example, he might be very protective of his 'territory' at Hogwarts, which could be his dorm or the Gryffindor common room.
Well, a really interesting plot twist could be his relationship with the other Hogwarts houses. He might not have the same automatic connection with Gryffindor. Instead, he could be more inclined towards Slytherin values, which would completely change his dynamic with Ron and Hermione. Maybe he would form closer friendships with Slytherin students right from the start. Also, his views on pure - blood supremacy could be more complex as he is raised in a family that might have some traditional views on blood purity.
Well, perhaps the nuns are in cahoots with some magical creatures. They could be working with a group of centaurs who have prophesied that Harry must be raised in seclusion among the nuns to gain a certain kind of purity of spirit. Then, when Harry finally enters the wizarding world, he has an aura about him that both attracts and confounds the dark forces. He might also have a special connection to the magical animals due to his time with the nuns, like being able to communicate with them on a deeper level, which would be really useful in his battles against the dark side.
A really interesting plot twist could be that the phoenix, being a symbol of rebirth, has the ability to make Harry remember his past lives. This would give him an edge as he could draw on the knowledge and skills from his previous existences. He might remember spells and strategies that were long forgotten, which would completely change the course of his fight against the dark forces.
One possible plot twist could be that Harry has unique magical abilities related to the ocean. For example, he might be able to communicate with sea creatures, which could help him in his adventures. Maybe he discovers a hidden underwater wizarding community that has been isolated from the rest of the wizarding world for centuries. Another twist could be that his enemies, like Voldemort, have a hard time reaching him in the ocean, but they find a way to use the ocean's power against him in some unexpected manner.
A really exciting plot could be that there is a prophecy that involves both Harry Potter and the goblins. The goblins have their own ancient prophecies that seem to connect with the ones about Harry. They have to work together to figure out what the prophecies mean and prevent a great disaster from befalling the wizarding world. This would involve a lot of research into old goblin and wizard lore, and they would have to travel to different magical places to find the missing pieces of the puzzle.
The plot could take a really interesting turn when it comes to Voldemort. Since Snape is raising Harry, he might train Harry in a way that Voldemort doesn't expect. Maybe Harry would be more of a spy in the dark side's camp. Snape could also use his position to mislead Voldemort about Harry's true abilities and intentions. This would create a whole new set of challenges and power dynamics in the fight against the Dark Lord. Harry's loyalties would be constantly tested, and his relationship with Snape would be even more crucial to the story.