In a team Iron Man time travel fanfiction, a great plot could be that Iron Man travels to the future by accident. There, he discovers a world in ruins because of some actions he took in his present. So, he has to travel back and correct those actions. He teams up with his past self and other Avengers from different time periods to make sure the future is saved. This would involve a lot of character development as the different versions of Iron Man and the Avengers have to work together and understand each other's perspectives.
One idea could be that Team Konohamaru travels back to the time of the First Hokage. They could witness the founding of Konoha and get involved in some of the early battles against rival clans. Maybe they help Hashirama in some way and learn valuable lessons about leadership and unity from him.
One idea could be to explore his origin story in more depth. Maybe he has a hidden family or a past trauma that shaped him into the man of iron. Another could be to put him in a different time period, like the future where technology has advanced even more and he has to adapt.
Maybe they time travel to a point where a major battle was lost in the past. Kakashi and Team 7 could change the outcome of that battle. For example, if they go back to the battle against the Nine - Tailed Fox when it first attacked Konoha. They might be able to prevent some of the destruction and save more lives. Or they could travel to a time when a powerful ninja was wrongly exiled, and they work to clear that ninja's name and change the course of history.
Perhaps they travel to a time in the past where a powerful and dangerous jutsu was first created. They have to stop the jutsu from being misused in the future. Along the way, they face challenges like dealing with the original creator who might not want to give up on his creation, and also face other ninja who want to steal the jutsu for their own evil purposes.
In some Iron Man harem fanfiction, it could be that Tony Stark is transported to an alternate dimension where the rules of relationships are different. There, he finds himself surrounded by female characters who are all vying for his attention. The story could explore how he navigates this new world and these new relationships while still trying to be the hero he is.
Well, a plot idea could be that in the fanfiction, the events of Iron Man 3 somehow get re - written in a way that Tony Stark's suits in that movie have a different origin. For example, they were actually created by an ancient civilization that he discovers accidentally, and this new knowledge ties into the Avengers' overall story arc. Also, we could have a story where the Extremis virus from Iron Man 3 spreads in a different way and starts to affect some of the other Avengers. This would force Iron Man to not only deal with his own problems related to the virus but also find a cure for his teammates. And then there's the idea of a parallel universe where Iron Man 3 never happened as we know it, but the Avengers are still dealing with the consequences of a similar threat, and they have to rely on Iron Man's knowledge from that 'alternate' Iron Man 3.
One idea could be Jarvis getting a physical form and having to learn how to interact in the real world like a human. He could struggle with emotions and social cues, creating humorous and touching moments as Iron Man tries to guide him.
A plot could also revolve around a time when Rescue's identity is compromised. Iron Man has to protect her while also trying to figure out who is behind the leak. They go on a journey that takes them to different parts of the world, facing various threats along the way. This would test their relationship and their ability to trust each other in difficult situations.
One idea could be to explore the backstory of the man in the iron mask more deeply. Maybe he has a secret family or a hidden past relationship that could change the whole perspective of his imprisonment. Another plot could involve a character who tries to rescue him not for political reasons but out of pure moral obligation and friendship.
Well, there could be a story where Iron Man and Nebula find themselves in an alternate universe. In this universe, they are the only ones who remember their original selves. They have to find a way to get back home while also dealing with the strange new versions of their friends and enemies. It could involve a lot of action and some really interesting character interactions as they try to adapt to this new and unfamiliar world.