One interesting plotline could be Harry mastering new and powerful magic that was not explored in the original books. For example, he might discover a long - lost spellcasting technique. Another could be his relationships with other characters evolving in different ways, like a deeper friendship with Neville or a different kind of mentorship with McGonagall.
Well, some fanfictions might have a plotline where Harry, as the master of Hogwarts, has to deal with a new dark threat that is more insidious than Voldemort. He could be using his unique position to reform Hogwarts' curriculum to better prepare students for all kinds of threats. Maybe he starts a new club that focuses on advanced defensive magic.
In some fanfictions within 'Harry Potter and the Legacy of Hogwarts', there could be a plot about time - travel. A group of students accidentally travel back in time and witness key events in Hogwarts' history. This could lead to them learning important lessons that they bring back to their own time. Or perhaps a plot where a new magical creature is discovered near Hogwarts and it has a special connection to the school's legacy. The students then have to protect the creature and in the process, learn more about the deep - seated magic that has been passed down through the generations at Hogwarts.
One interesting plotline could be Harry using his 'ownership' to reform the Hogwarts curriculum. He might introduce new classes like Muggle Studies for wizards to better understand the non - magical world. Another could be him using his influence to improve the living conditions for house - elves at Hogwarts, as he has always been sympathetic to their cause.
One interesting plotline could be a magical adventure where Harry Potter and the Lady of Hogwarts team up to discover a long - lost secret within the castle. Maybe they find a hidden chamber that holds the key to an ancient magic that can save Hogwarts from a new dark threat.
A possible plotline could be that Hogwarts itself becomes a sort of magical battleground earlier than expected. The Death Eaters try to take over the school completely, and the students and remaining teachers have to fight back in a sort of guerilla warfare within the castle walls. This would change the whole dynamic of the seventh year, with classes being interrupted and students having to use their magic in real - life combat situations.
One interesting plotline could be exploring how the blood wards affect characters other than Harry. For example, how they might impact students who have a connection to dark magic in their family history but are still good at heart. Maybe they experience strange phenomena around the wards. Another could be about the origin of the blood wards and a fanfiction could delve deeper into the magic and rituals that created them in the first place.
A great plotline in such fanfiction could be a Potion Master being framed for creating a harmful potion. The real culprit might be someone trying to discredit the Potion Master for personal gain, like a rival for a teaching position at Hogwarts. The Potion Master then has to prove their innocence while also dealing with the chaos that the false accusation has caused in the wizarding community. They might have to enlist the help of their students or former colleagues to clear their name.
In some fanfictions, Harry's time - mastery allows him to interact with past versions of himself. This can create really complex and mind - bending scenarios. He could use these interactions to gain wisdom from his past experiences more directly, or to give his past self crucial information that would help him in his battles against Voldemort. For instance, he might tell his younger self about a hidden weakness of a particular Death Eater that he discovers in the future.
Perhaps a plot where Harry uses his mastery of snakes to uncover ancient secrets in Hogwarts. He could find hidden passages or long - forgotten magic related to snakes that no one else knew about. This would not only add to his own power but also change the dynamics of the wizarding world as they know it.
In some fanfictions, Harry's mastery of illusions might lead to him being able to enter people's dreams and manipulate them. He could use this power to either help his friends overcome their fears or to gather information from the enemy. However, he would also have to face the moral implications of such actions.
One interesting plotline could be Harry fully exploring and mastering the powers that come with being the Master of Death. He might use these powers to reshape the wizarding world in ways that were not possible before, like eradicating dark magic at its source.