One possible plotline could be that Harry obliviates himself to forget a great tragedy. Maybe he loses a dear friend in a battle and can't bear the pain, so he decides to erase his memory. He then has to start anew, and the story could be about his journey to regain his true self without his memories. He might make new friends who notice something strange about him and try to help him remember.
Another plot could be that Harry obliviates himself on accident. He was trying to perform a different spell, but something went wrong. Now, his friends in Hogwarts have to figure out how to reverse it. They search through old books, consult with professors, and go on little adventures to find the ingredients or knowledge needed to bring Harry's memories back. Along the way, they also learn more about Harry's true self and the importance of his memories.
Perhaps Harry obliviates himself to protect a secret. He could have discovered something dark and dangerous about the wizarding world that powerful forces don't want him to remember. As he tries to live his obliviated life, he starts to have strange dreams or instincts. These could lead him to gradually piece together his forgotten past, all while being hunted by those who want the secret to stay buried.
Another plot could involve a sort of magical exchange. Orochimaru, being a master of some dark and strange jutsu in his own world, might offer to teach some of his knowledge to certain dark wizards in the Harry Potter world in exchange for something valuable. Harry Potter and his friends would have to prevent this knowledge transfer as it could tip the balance of power towards the dark side in their world. They might need to seek help from some of the more powerful and wise wizards like Dumbledore to outwit Orochimaru.
Another plot could involve Medusa being a part of a long - forgotten magical mystery that is somehow related to Harry's destiny. Harry, with his inquisitive nature, starts to research about her. As he gets closer to the truth, he has to face the danger of being turned to stone. But through his courage and the help of his friends, he manages to break the curse on Medusa, and in return, she helps him in his fight against Voldemort.
One possible plotline could be that Uncle Matthew Potter has some long - lost magical power or artifact that the main characters need to find. This could lead them on an adventure through different parts of the wizarding world. Another plot could involve him having a secret connection to a dark wizard from the past, and the story could be about uncovering this connection and dealing with its consequences.
One possible plotline could be that Harry discovers he has Lamia heritage. This could lead to him having different magical abilities related to Lamia, like the power to charm or hypnotize. He might face discrimination from some in the wizarding world who fear the unknown Lamia powers.
One possible plotline could be that Harry discovers a zanpakuto in the Forbidden Forest. He has to learn how to use it while still dealing with the threats from Voldemort. Maybe the zanpakuto has some special powers that can help him in his fight against the Dark Lord.
Perhaps in this fanfiction, there is a spell gone wrong that merges Harry Potter with Alucard. Harry now has to deal with the new instincts and powers that come with being part - Alucard. He has to hide his new identity from his friends at Hogwarts while also trying to figure out how to use his combined powers to protect the wizarding world. There could be a sub - plot where some of the Hogwarts faculty suspect something is different about Harry and start to investigate, adding to the tension and drama of the story.
One possible plotline could be that Harry discovers he has Nephilim blood. This newfound heritage gives him powers beyond what normal wizards have, and he has to struggle with how to control and use them while still fitting into the wizarding world. He might face discrimination from some wizards who fear his new abilities.
Maybe Harry, as a politician, has to deal with the aftermath of the war. He could be trying to unite different factions within the wizarding community that were divided during the battle against Voldemort. He might face opposition from traditionalist wizards who don't want to see the changes he is proposing, such as equal rights for house - elves or better integration of muggle - borns into the wizarding society. And he would have to use his charm and the respect he has earned from his heroic deeds to convince others to support his political agenda.
One possible plotline could be Harry using his newfound baron status to reform the wizarding world's social structure. He might try to bring more equality among pure - bloods, half - bloods, and Muggle - borns. Another could be him having to deal with the political intrigue that comes with being a baron, like rivalries with other noble wizarding families.
Well, perhaps there could be a plot where the virus is actually a dark magic - created plague. The Ministry of Magic is in chaos as they try to deal with it, and it's up to Hermione to research and find a solution using her vast knowledge of magic. Or maybe the virus is spreading among the Muggle - borns first, and Ron has to deal with his family's concerns while also trying to help his Muggle - born friends. There are many directions it could go depending on the creativity of the author.