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.
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.
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.
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.
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.
Another plot might involve the Avengers trying to figure out how to deal with de - aged Tony and Loki. They could be worried about Loki's intentions since he's usually a villain, but at the same time, they have to take care of a child - like Tony. This creates a lot of comical and tense situations.
Fanfiction.net is also a place to look. There are many writers who contribute to different fandoms. However, the search function might not be as advanced as AO3. But still, it's worth a try to find 'de aged tony and loki fanfiction'.
One popular 'tony gets de aged fanfiction' is 'A Younger Tony'. It explores how Tony Stark's character changes when he's de - aged. His genius is still there but expressed in a more innocent and unfiltered way. Another one could be 'De - Aged Genius' which delves into the chaos and also the new opportunities that come with a younger Tony in the Stark Tower.