One possible reason could be that Tony initially misunderstands Spiderman's actions. He might think Spiderman is doing something wrong when in fact he's not, and then later realizes his mistake and tries to make it up by helping him. For example, if Spiderman is involved in a situation where it looks like he's causing destruction, but it's actually part of a bigger plan to stop a greater evil.
It could also be a matter of guilt. Tony might have done something in the past that indirectly led to Spiderman getting hurt. To redeem himself, he decides to offer his help. This could be related to some experiment or technology that Tony developed which backfired on Spiderman, and now he wants to fix the situation.
In some fanfictions, Tony might help Spiderman by providing him with advanced technology. For example, he could give Spiderman a new suit with enhanced features like better web - shooters or stronger defense mechanisms. This would help Spiderman in his battles against various villains.
One reason could be a false accusation. If Spiderman is wrongly accused of a crime by the Avengers or someone within the Avengers' circle, he might feel betrayed and lash out at them. He's just a young hero, and such a false accusation could really make him angry.
Well, perhaps Spiderman is poisoned by a new type of toxin from a villain. The Avengers then scramble to find an antidote. Black Widow uses her espionage skills to track down the origin of the toxin, while Hulk, in his Banner form, tries to analyze it scientifically. Thor might also use his Asgardian knowledge to see if there are any magical cures. In the meantime, they keep Spiderman comfortable and safe from further attacks.
One reason could be a misunderstanding. Maybe some villain has tricked Hulk into believing Spiderman is a threat. For example, the villain might have faked some evidence to make it seem like Spiderman was planning something bad against Hulk or his friends.
One possible reason could be the physical injuries he sustained during the fight in Siberia. The intense battle might have left him with wounds that continue to pain him. Another reason could be the emotional betrayal he felt, especially if in the fanfiction his friends turned against him during that event, which would deeply wound him psychologically.
One reason could be to explore the darker side of the characters. Some fans like to see how the Avengers could be pushed to their limits and do something out of character, like hurting Tony as a teenager. Another reason might be to create a more angsty and emotional story, with Tony as a victim and the Avengers as the antagonists, which can add a lot of drama.
One possible reason could be a miscalculation in a joint mission plan. Maybe Tony and Clint had different ideas on how to approach a situation, and Tony's plan, which was ultimately followed, led to Clint being in a vulnerable position and getting hurt.
One reason is that some fanfiction authors may lack a deep understanding of Naruto's character. They might write things that are completely contrary to his values and personality just for the sake of creating a 'unique' story. For example, Naruto is known for his positive attitude and strong will, but in some fanfictions, he could be depicted as a negative or spineless character.
One reason is that batjokes may not fit the mood of the fanfiction. Fanfiction often has its own atmosphere and theme. If batjokes are too comical or out of place in a more serious - themed fanfiction, it can ruin the overall feeling. For example, in a dark and gritty Batman - related fanfiction, a silly batjoke can break the immersion.
In some Spiderman fanfiction, Flash might help by providing an unexpected ally. For example, he could use his popularity or resources to assist Spiderman in a difficult situation. However, Flash often hurts Spiderman in fanfiction too. His bullying nature can lead to Spiderman's self - doubt or put him in dangerous situations, like when Flash's actions draw unwanted attention to Spiderman's secret identity.