The plot might take a darker turn. Harry's condition could make him weaker and more vulnerable, and his enemies could take advantage of this. His friends might have to fight to protect him while also trying to find a way to heal him. It could also lead to a situation where Harry has to make difficult decisions about his own health and the safety of others.
It could lead to a journey where Harry has to find a specific healer or a magical place that can cure him. Along the way, he might face more challenges and discover secrets about his condition or the magical world.
The other characters could rally around him to find a cure. They might search for ancient spells or potions to heal him.
Well, it could lead to a lot of self - discovery for Percy. He might start to question his own mortality and his role in the story. This could make him more determined to fight against whatever is causing his condition. His relationships with other characters could also change. Some might become more protective, while others might be afraid to get too close in case they catch whatever is wrong with him.
It could be a new dark wizard. There are always new threats emerging in the fanfiction world. This new dark wizard might have a vendetta against Harry and uses a special spell or potion to make him cough up blood.
Often, his friends would rush to his aid. They might try to find a cure or figure out what's wrong with him. Maybe Hermione would start researching in the library right away.
The plot could involve Amy Fleming having a mysterious illness that causes her to cough, and her friends and family are worried. They try to find a cure while she continues with her daily life, struggling with the cough.
Well, it could be related to some sort of poison. Perhaps he was poisoned by an enemy who managed to slip something into his food or drink. The poison could be slowly corroding his insides and making him cough up blood as a symptom. It might also be part of a plot by a new villain in the fanfiction world who is trying to weaken Harry in a more insidious way than the usual dark wizards.
The plot could start with a mysterious portal opening between the two worlds. A Hogwarts student might accidentally stumble through it into the world of Strike the Blood. This would lead to a series of adventures as they try to find their way back home. Along the way, they could meet the characters from Strike the Blood and learn about their world. The student could also introduce some basic magic concepts to them. As news of this strange visitor spreads, it could attract the attention of both the good and bad forces in the Strike the Blood world, creating a lot of tension and action.
It could lead to a discovery of a hidden plot against Harry. His coughing up blood might be a sign that there is a much bigger conspiracy at play, perhaps involving someone close to him who wants to weaken him for some ulterior motives.
Often, it starts with the incident that causes the concussion. Then it shows how Harry's daily life is disrupted. For example, he may struggle in his classes or have difficulty with his Quidditch training.
In 'pregnant Harry fanfic', the plot may develop around the mystery of who the mother is if it's not an obvious pairing. There could be a search for the truth, and all the while, Harry has to deal with the implications of the pregnancy on his life and his standing in the wizarding world.
The plot could involve a mystery surrounding this person with the blood of the four houses. They could be hunted by dark forces who want to use their special blood for evil purposes. At the same time, they are trying to uncover secrets about their heritage within the four houses.