In this type of fanfiction, a possible plot is that the Death Eaters and the Order of the Phoenix members are forced to live together in a 'Big Brother' style house. They have to follow certain rules set by the magic of the house. There are tasks related to both dark and light magic. The characters have to balance their own beliefs and goals while also trying to win the overall competition. This creates a lot of tension and interesting character interactions as they all have very different motives.
In some fanfictions, the older brother could be an outcast from the wizarding world due to a misunderstood magical ability. He then takes Harry under his wing and shows him a different side of magic, one that is not taught at Hogwarts. They might go on adventures together outside of the school, exploring ancient and forgotten magical places, and in the process, the older brother helps Harry become a more well - rounded wizard.
Perhaps the plot could involve the Hogwarts houses competing like 'Big Brother' contestants. Each house has to strategize, form alliances, and complete tasks to avoid being 'evicted'. Harry could be a key player in Gryffindor's strategy.
One idea could be a story where a new housemate has a secret superpower that they have to keep hidden while in the Big Brother house. Another could be a fanfiction about a past housemate returning in a different role, like as a guest host. Or perhaps a story where two housemates form an unlikely alliance based on a shared love for a particular type of music that they discover in the house.
A great plot for a Potter Manor fanfiction could involve a mystery that surrounds the manor. For instance, strange noises at night lead Harry to uncover a long - forgotten chamber. It could also be about Harry restoring the manor to its former glory, perhaps with the help of Hermione's research on ancient magic used in the construction of such manors.
A cool plot could be that they are brought together by a prophecy. Percy's skills with water and Harry's magic would be combined to defeat an ancient evil. They might start by being suspicious of each other, but as they learn about their shared heritage, they grow closer. Also, there could be a plot where they have to deal with the politics of both their worlds. How would the wizards react to the existence of demigods and vice versa? This could lead to some really interesting character interactions and story developments.
A fun idea could be that the Big Bang Theory characters travel back in time and end up in the era of the founding of Hogwarts. They could meet the four founders and try to introduce them to modern scientific concepts. This would lead to some really interesting interactions as the wizards are trying to understand things like electricity and gravity.
A great plot idea could be Percy having to deal with the jealousy of other demigods because of his special status as the 'brother' of the Big Three. This could lead to some tense relationships and even battles within Camp Half - Blood. Or perhaps Percy is forced to make a difficult choice between loyalty to his mortal friends and family and the demands that come with his connection to the Big Three. Maybe there's a story where Percy uncovers a secret power that only he, as related to the Big Three, can access, but it comes with a great cost.
One idea could be that Big Brother is a protector in the BioShock world, guiding Little Sister through the dangerous and strange underwater city. He helps her avoid the Splicers and find the ADAM she needs in a more ethical way, like by using his combat skills to take out the Big Daddies first so she can harvest safely.
Perhaps Harry gets into a time - travel adventure and meets a younger James. He has to navigate the situation without revealing their future relationship. This could lead to some comical and heart - warming moments as Harry sees a different side of his brother before all the fame and heroics.
Well, a really interesting plot could be set in a magical world where James has a special power that Harry doesn't understand at first. Harry then embarks on a journey to figure it out and in the process, they discover a long - lost family secret. It could also be a story about how they deal with the loss of a loved one together. Harry being the more emotional one and James trying to be strong for him. And then they grow closer through this difficult time.