One possible scenario in this fanfiction could be that a de - aged Tony Stark brings a new perspective to the events of Civil War. He might be less jaded and more idealistic, trying to find solutions that the older, more conflicted Stark couldn't see. Maybe he forms unexpected alliances with other characters based on his fresh outlook.
The de - aged Tony could also form a mentor - mentee relationship with a younger Avenger. He has the knowledge and experience of his older self but the energy and fresh perspective of his de - aged self. This relationship could be a key factor in how the story progresses, as he imparts his wisdom in a different way and the younger Avenger helps him see things from a new angle, which could potentially change the course of the Civil War in the fanfiction.
There's a fanfic called 'De - Aged Stark's New Adventures'. In this story, de - aged Tony forms an unlikely friendship with a young inventor. They work together on projects that could change the world. It's interesting to see how Tony's adult knowledge combines with a child's creativity in this one.
The 'family - like bond' trope is often seen. De - aged Tony forms closer bonds with the people around him, almost like a family. They protect him and he in turn, uses his genius to help them. For instance, he might become like a little brother figure to some characters. And there's also the 'coming - of - age' trope even though he's already an adult. He still has to grow in this new de - aged state, learning new things about himself and the world.
A possible plotline is that the de - aged Peter and Tony have to work together to solve a problem that only their combined knowledge, both from the present and Peter's future - self's knowledge, can fix. For example, they might need to stop a villain who has a time - related weapon that de - aged Peter in the first place. This would involve Peter using his spidey - sense in a different way as a kid and Tony using his tech skills to analyze the weapon and figure out how to reverse its effects not just on Peter but also on any other potential victims.
At first, Tony might be skeptical about the whole situation. But as he sees the de - aged Peter's potential and his spidey - sense in action, he starts to warm up. They could develop a relationship where Tony is constantly protecting Peter from both physical threats and the knowledge of the future that Peter might accidentally reveal. Peter, on the other hand, would be in awe of Tony's intelligence and resources and would try to learn as much as he could from him. Their relationship would be a mix of mentorship, friendship, and a bit of a father - son dynamic.
In some fanfictions, Zemo - the one who originally stirred up trouble in the movie Civil War - could still be a major antagonist. He might target Peter specifically to get to Tony or use Peter's inexperience against the heroes.
A fanfiction with Tony Stark having a heart attack during Civil War can open up numerous storylines. It could show the reactions of other characters like Pepper Potts, who would be extremely worried. His fellow Avengers might put aside their differences temporarily to ensure his survival. Also, it could lead to a deeper exploration of Tony's health issues that were perhaps overlooked before the heart attack, and how it affects his future decisions in the ongoing conflict.
One common theme is the exploration of Tony's lost innocence. When he's de - aged, he gets a chance to experience things in a new light. Another theme is the impact on his relationships. For instance, his relationship with Pepper might take on a different dynamic as he's now younger. Also, there's often the theme of self - discovery. Tony may find out new things about himself that were buried under years of being an adult.