There is a fanfiction that explores the idea that Quirrell was not completely powerless during the possession. It presents a scenario where he has some control over his actions and tries to secretly undermine Voldemort. This gives a whole new twist to the traditional view of the possession.
One fanfic I read focused on the relationship between Quirrell and the students during his possession. It shows how the students start to suspect something is wrong with him. The story details their investigations and how they gradually figure out that he is possessed, which is a really cool take on the whole concept.
A great one is 'Quirrell's Hidden Struggle'. In this fanfic, it really shows how Quirrell's personality changes as he gets possessed. You can see the transformation from a timid professor to a more menacing figure under Voldemort's influence. It's interesting to see how the author plays with his character development.
In some fanfictions, like 'The Unforeseen Consequences of Time Travel', a plot twist could be that when Harry and Hermione go back in time to save someone, they end up causing more harm than good. This completely flips the expected outcome on its head and makes for a very engaging read.
Another plot might involve a character other than Voldemort using the Killing Curse in a moment of extreme desperation. For example, a Hogwarts student who is being blackmailed by Death Eaters and uses it to defend themselves, but then has to deal with the moral and magical consequences. It could show the dark side of the wizarding world even among the so - called 'good' characters.
In certain fanfictions, a really interesting plot twist is when Harry Potter is sent back in time and ends up influencing Tom Riddle's early life in ways he didn't anticipate. This can lead to a completely different Hogwarts and wizarding world. For example, Harry might accidentally introduce a new form of magic that Tom then misuses. Or, there could be a plot twist where Tom Riddle's Horcruxes have an entirely different origin or purpose than in the original books, which throws Harry's understanding of how to defeat him into chaos.
One interesting Harry Potter possession fanfiction could be 'The Possessed Heir'. It explores a scenario where Harry is possessed by an ancient magic that changes his personality and powers. Another might be 'Possession of the Potter' which delves into a dark entity taking over Harry and how his friends try to save him. And 'Unexpected Possession in Hogwarts' where a student other than Harry gets possessed and it has a ripple effect on the whole school.
A really unique part of these fanfics is how they can change our perception of Quirrell. Instead of just seeing him as a simple villain, they can show his inner turmoil. Some fanfics might depict him as a victim of certain circumstances or having a more complex moral compass. Also, the relationships he forms in fanfics can be different from what we expect. He might have unexpected friendships or alliances that add new layers to the story.
Some fanfics might explore Nagini's connection to the other Horcruxes. Since she was the last Horcrux to be destroyed, perhaps there was some kind of communication or power exchange between her and the other Horcruxes that we didn't see in the books. This could add a whole new layer of mystery to the story.
The plot where Murtagh teaches Harry some of his unique magic techniques is really cool. It shows how different magical systems can interact. For example, in a fanfic I read, Murtagh showed Harry how to use a spell that was common in his world but unheard of in Hogwarts.
Well, one intriguing plot is when Harry time travels and has to hide his true identity as a Gryffindor - turned - Slytherin. He has to act like he belongs there while secretly trying to figure out how to get back to his own time. Another plot could be that his time travel into Slytherin causes a rift in the timeline, and he has to fix it before everything goes wrong. For example, in some fanfictions, his presence in Slytherin changes the relationships between the houses and he has to make sure the good guys still win in the end.
In some fanfictions, they might rewrite the possession scene completely. Instead of the typical way it was shown in the books, they could add new magical elements. Maybe Quirrell has some hidden magic that reacts to the possession, creating a more complex and engaging story.
Perhaps a storyline where Fem Harry discovers a connection between the magic in the Harry Potter world and the arcane powers in Warhammer. She could then embark on a journey to understand this connection better, facing challenges along the way. She might meet characters from both universes who either help or hinder her in this quest, making for a very engaging fanfiction.