Well, perhaps a plot point could be the reactions of the Kwamis. When Adrien and Gabriel swap, the Kwamis that are used to one person's personality and way of doing things would have to adjust. For example, Plagg might be really confused with Gabriel in Adrien's body. Also, the way they use the Miraculous powers could change. Adrien might use the powers in a more positive and heroic way compared to Gabriel's more self - centered motives in the original role.
The father - son relationship would be completely turned on its head. Instead of Gabriel being the strict and often distant father, Adrien would be in that role. He might be more understanding and lenient towards himself (in Gabriel's body). And Gabriel, as Adrien, would have to deal with a father - like figure in Adrien's real father. This would create a very strange and new dynamic between them.
Gabriel could be an original character created by the fanfiction writer. Maybe he's a powerful and reclusive wizard who lives on the outskirts of the wizarding world.
Gabriel Fernandez was a young boy who was a victim of severe abuse. His case became well - known because of the system's failure to protect him, and his teacher was one of the people involved in the discovery of the situation he was in.
In this fanfiction, Gabriel could be an original character created by the author. He might be a powerful wizard with a mysterious past. Maybe he was once a great hero or a feared dark wizard, and his connection to Harry is what makes the story so interesting.
In 'Ava and Gabriel a love story', it could be that Ava and Gabriel are from different worlds. Ava might be a free - spirited artist while Gabriel is a more reserved academic. But one day, they are brought together by a common friend at a party. At first, they don't seem to have much in common. However, as they start to have conversations, they find that they are both passionate about a certain cause, like environmental protection. This shared passion becomes the foundation for their relationship and soon enough, love blossoms between them.
You can try looking on popular fanfic websites such as Archive of Our Own (AO3). It has a large collection of fanfictions, and there's a good chance you'll find a Gabriel x Vinette fanfic there. Just use the search bar and type in the relevant tags like 'Gabriel Dropout', 'Gabriel x Vinette' and see what pops up.
He might be an old friend of Harry's parents who was thought to be dead. But he resurfaces and has a lot of knowledge about James and Lily Potter that he shares with Harry. This knowledge could help Harry in his fight against the remaining dark forces in the wizarding world.
A good fanfic in this pairing often has well - developed characterizations. It should capture the essence of Gabriel and Vinette's personalities as seen in the original series. For instance, Gabriel's lazy - yet - secretly - caring nature and Vinette's sweet and somewhat naive personality.