In the fanfiction, it could be that Harry's learning of Black family magic unlocks a new power within him. This power could be related to his connection with the Black family through Sirius. He may then use this power to fight against the rising dark forces in the wizarding world, in a way that is different from the traditional magic he has been taught.
One great plot development could be that the elemental magic Harry learns is not part of the traditional Hogwarts curriculum. So, he has to seek out hidden mentors or ancient texts. This could lead to him exploring parts of the wizarding world that are long forgotten. As he delves deeper into elemental magic, he might also start to question the limitations of the magic he has been taught so far at Hogwarts.
In some fanfictions, Harry might use necromancy to bring back important figures like his parents. This could lead to complex emotional and moral dilemmas as he tries to interact with them in a world that has moved on without them.
Well, he might use soul magic to communicate with the spirits of the dead wizards. It could give him an edge in battles as he might understand the essence of his opponents' souls.
Well, one possible plot development could be Harry struggling to control his newfound ability at first. He might accidentally change his appearance in embarrassing situations, like during a Quidditch match or in front of his crush. Another could be that he discovers he has a special connection to other metamorphmagi in the wizarding world, leading him on a journey to find out more about his heritage.
In this type of fanfiction, a great plotline could be that Harry stumbles upon a hidden family grimoire. Inside, he finds magic that was thought to be lost. For example, there could be spells for creating protective shields that are stronger than any known spell. Or perhaps he discovers family magic that is related to time - travel, which he then has to learn to control carefully so as not to disrupt the timeline. This discovery of family magic would add a whole new layer to his character development and his role in the wizarding world.
In some fanfictions, Harry might learn family magic that has to do with time manipulation. His family could have had a special talent for seeing into the past or future. As he delves into this magic, he has to learn to control it carefully, as misusing time - related magic can have serious consequences. He may use this new - found magic to prevent certain disasters or to gain knowledge from the past that could change the course of the wizarding world.
He could lose his friends. In the original story, his friends stand for good and oppose black magic. If Harry starts learning it, they might turn their backs on him. Also, he could be ostracized by the wizarding community. The wizarding world has a clear stance against black magic, and Harry would become an outcast.
Another idea could be Harry learning magic from a time - traveling wizard from a far - off future. This would introduce futuristic magical concepts and technologies that he would have to adapt to. It could also lead to him having to use his traditional Hogwarts magic in new and unexpected ways to keep up with the advanced magic he's learning.
One interesting story could be Harry's initial struggles. He might face challenges like accidentally causing chaos as he tries to control his wandless magic. For example, he could make objects fly uncontrollably in the Gryffindor common room. Another aspect could be his secret training sessions. He might find a hidden place in Hogwarts, like an abandoned classroom, to practice without others knowing.
There are fanfictions where he learns elemental magic in a new way. For example, being able to combine fire and water magic in a unique and powerful way that was not explored in the original books. He could use this to create new defensive or offensive spells against dark wizards.