Perhaps they'll be so into the fanfictions that they'll try to incorporate some of the fictional elements into their real lives. For example, if there's a fanfiction where Tony has a unique way of powering up his suit, they could try to replicate it in a way that's applicable to their own tech. It could also strengthen their bond with Tony as they get more insights into his character through these fictional works.
First of all, the Avengers realizing they need Tony fanfiction could be a sign that they are missing him deeply. They might read these fanfictions to relive the memories of their time with Tony. In the fanfictions, they could see different versions of Tony's relationships with each of them. It could make them appreciate their friendship with him more. Also, the fanfictions could offer new perspectives on Tony's genius, which might help them in their future endeavors. They could even share these fanfictions among themselves and have discussions about how the stories could have been different in real life.
In a fanfiction where Tony didn't die, he could continue to be a mentor to the new generation of Avengers. He would use his genius intellect to develop even more advanced technology to protect the Earth. Maybe he'd finally have the time to focus on his family life with Pepper and their daughter, while still being involved in superhero affairs on a more strategic level.
It could bring them closer. By reading and discussing Tony fanfiction, they'll be focusing on a common interest related to one of their own. This shared experience can enhance their sense of unity.
In this fanfiction scenario, Peter himself would likely go through a lot of changes. He might feel a new sense of pressure, knowing that he is now seen as Tony's son by the Avengers. He could also feel more accepted into the group, like he truly belongs. There could be heart - warming moments where the Avengers share stories about Tony with Peter, helping him to understand his father better and grow into his own as a hero.
Another aspect could be the emotional turmoil for the other Avengers. They would surely be scrambling to find Tony. Captain America might feel especially guilty, considering their past differences. The team would have to put aside their differences completely to rescue Tony. They might start by gathering intel on Thanos' whereabouts and formulating a plan that involves their unique skills. For example, Black Widow could use her espionage skills to infiltrate Thanos' base, while Thor could provide the brute force needed in a direct confrontation.
The story could also take a more dramatic turn. The child might develop some sort of special powers or abilities due to Tony's genes or the unique circumstances. This could attract the attention of new villains or other powerful entities, forcing Tony to not only protect his child but also the world from any potential threats that come as a result of the child's newfound powers.
The OC might find themselves in a really strange situation. Loki could be using the OC as a pawn in a bigger scheme against the Avengers. He might try to use the OC to get some valuable information or as a bargaining chip. The OC, on the other hand, could be trying to outwit Loki, using their own wits and any knowledge they have of the Avengers' world. It would be a battle of intelligence between the OC and Loki.
Well, she could be rescued by one of the Avengers. Maybe Thor shows up with his lightning powers and uses them to stop any further danger around the crashed car. Then he could take her to safety and get her medical help.
Well, a lot could happen. Maybe the abused reader finds solace and protection among the Avengers. For example, if it's a story where the reader has superpowers but has been abused because of them, the Avengers could help the reader control and embrace those powers. They might offer a sense of family and belonging that the reader has never had before.
Well, it could be a very emotional encounter. Maybe there would be some initial shock and disbelief. The parents might be overjoyed to see their children, who have become Avengers. There could also be some conflicts as the parents try to impose their old values on the Avengers, while the Avengers have their own new ways of thinking.
The story could focus on Tony's downward spiral into guilt and self - blame. He might isolate himself from the other Avengers, feeling that he should have been the one to die. His technological advancements could take a dark turn as he tries to find a way to bring Peter back, perhaps even dabbling in dangerous and unethical science.