His anger could drive him to take risks he wouldn't normally take. Maybe he decides to go after a powerful enemy on his own without proper backup because he's so angry that he doesn't think clearly. This could put him in great danger and also change the course of the story as the other characters then have to scramble to save him.
It could lead to a lot of conflict. His friends might try to reason with him, but if he's too angry, he might push them away. This could split their group apart, creating new alliances or just leaving Harry isolated for a while. His anger can also attract the attention of the wrong sort of people, like those who want to use his emotional state for their own gain.
The protective brother can change the plot significantly. For instance, if he's highly skilled in magic, he can prevent Harry from getting into some of the dangerous situations he faces in the original series. He might be able to stop Harry from entering the Triwizard Tournament by interfering with the Goblet of Fire's magic. This would then change the entire course of that year at Hogwarts and Harry's relationship with Cedric Diggory and others.
It can create immediate conflict. If a young wizard performs magic accidentally, the Trace can bring the Ministry's attention, like in some fanfics where a minor character's small magic act sets off a chain of events because the Ministry gets involved.
The 'darkness' can make the plot more complex. It might introduce new challenges for the characters that they have to overcome. For example, if there are new dark spells or dark creatures in the fanfiction, the characters need to find ways to deal with them.
The pet might cause trouble for Harry. Imagine it has a mischievous streak and keeps getting into places it shouldn't be, like the Slytherin common room. This would lead to all sorts of awkward and dangerous situations for Harry, forcing him to come up with creative solutions to get out of trouble.
The concept of Harry as a pyromancer can change the fanfiction plot in many ways. Firstly, his battles would be different. He could use fire to his advantage, which might make him more of a force to be reckoned with. Secondly, his relationships with other characters could shift. Some might be jealous of his new power, while others could be more drawn to him. Also, it could introduce new elements to the overall story, like a search for the origin of his pyromancy powers or a need to control them better to avoid causing accidental destruction.
Well, in many Harry Potter fanfictions with time travel, it can completely change the plot. For example, if a character goes back in time and warns Harry about certain events before they happen. It might prevent some tragedies or create new situations. Maybe they could stop Cedric's death by changing the events in the Triwizard Tournament. This adds a whole new layer of complexity and excitement to the story.
Well, it can create a lot of chaos. For example, his friends like Hermione and Ron would be desperate to find him. They would start their own investigations, which could lead to many new adventures and discoveries. Maybe they'd find out about some long - hidden secrets in the wizarding world in their search for Harry.
It can change the whole dynamic. For example, if a character gets access to divine energy, they might be able to easily defeat enemies that were previously unbeatable. This could lead to a quicker resolution of conflicts or create new ones as other characters might be jealous or afraid of this new power.
Forbidden love can be a major driving force in the plot. It often creates conflict. For example, if two characters from rival houses, like Gryffindor and Slytherin, fall in love, it can cause problems within their friend groups. Their friends might try to keep them apart, leading to drama and tension.