In this fanfiction, a really engaging plot development could be the discovery of a hidden connection between the demon and Harry's past. Maybe the demon was once summoned by one of Harry's ancestors and now it's seeking revenge on the Potter family through Harry. As a result, Harry has to not only fight the possession but also uncover the secrets of his family's history to break free from the demon's hold.
One interesting plot development could be Lloyd's struggle to regain control. As he's possessed, his friends might initially not realize it and think he's just acting out of character. Then, they gradually notice the strange behavior and start to investigate. This could lead to a race against time to save Lloyd from the possessing force.
In some versions, Harry might struggle with the internal conflict of having the Dark Mark. He could face discrimination from those who believe he has truly turned to the dark side. This could lead to a situation where he has to prove his innocence while also dealing with the newfound power or connection that the Dark Mark might bring.
Well, one possible plot development could be that when Harry gets his parents back, they have to quickly adapt to the modern wizarding world. His parents were from an earlier time, so things like new spells and magical devices might be quite a shock for them.
Dumbledore could be the key character. He's extremely powerful and knowledgeable. He might sense that something is wrong with Harry and use his vast magical abilities and wisdom to find a way to exorcise the demon. He could also call on the help of other powerful wizards or even use some ancient magic artifacts to save Harry.
One possible plot development could be the initial shock and confusion from both Draco and Harry. They would have to deal with the reactions of their friends and the wizarding community. Another could be the struggle to find a way to handle the pregnancy in a world where male pregnancy is unheard of, perhaps seeking out rare magic or potions. Maybe there would be a plot where they have to keep it a secret from their enemies who could use this strange situation against them.
In some 'Nightwing gets captured' fanfictions, he might be captured by a powerful villain like Deathstroke. This could lead to intense fight scenes when his friends come to rescue him. For example, Batman and Robin might team up, using their detective skills to find Nightwing's location.
In some 'Adrien gets akumatized fanfiction', his akumatization could be caused by a misunderstanding with his father. This could lead to his akumatized form having powers related to control or isolation, like being able to trap people in a sort of prison made of his negative emotions. The story could then focus on how Marinette, as Ladybug, tries to reach out to the real Adrien inside the akumatized form. She might have to dig deep into their relationship and use memories they've shared to break through to him.
In certain fanfictions, Dumbledore could get caught in a lie. Maybe he told the students one thing about a particular magical artifact, but then was caught when it was revealed he knew more than he let on. This would create a lot of drama as the students and other faculty members might lose trust in him for a while.
One plot development could be that Hiccup discovers an ancient technique for building stronger dragon saddles. This new saddle design not only gives him better control over Toothless but also allows him to perform more advanced maneuvers. As a result, he becomes a more formidable rider and his reputation as a dragon trainer grows.
Another aspect could be related to his family heritage. Harry could inherit a special magical artifact that was passed down through the Potter family. This artifact might hold the key to some long - forgotten magic or a prophecy. As he explores his inheritance, he uncovers secrets about his family's past and its connection to the overall history of the wizarding world, which in turn helps him in his fight against Voldemort.