Their relationship could develop in a mentor - mentee way at first. Tony would teach Peter about science, technology, and how to be a better superhero. As time goes by, they would become more like father and son. Peter would start to look up to Tony not just as Iron Man, but as a dad. For example, they might have movie nights together or Tony would help Peter with his school projects.
One possible plot twist could be that Peter's real identity as Spider - Man is revealed to Tony in a very unexpected way. Maybe during a fight against a common enemy, Peter's powers malfunction and he has to expose his identity to save Tony. Another could be that Tony's enemies try to use Peter against him once they find out about the adoption. For example, they kidnap Peter to blackmail Tony into giving up some important technology.
There are often a lot of action - packed scenes in these fanfictions too. Since Tony has all his Iron Man tech and Peter has his spider - powers, they can team up against powerful villains. Imagine them taking on a new super - powered foe that neither could handle alone. Their combined skills and the banter between them during the fight make for some really exciting reading.
Other Avengers might interact with Peter too. For example, Rhodey could befriend Peter and train with him. Or Natasha could teach Peter some spy skills, which could be useful for his superhero activities.
Maybe in the fanfiction, Tony discovers Peter's potential not just as Spider - Man but also in other areas like science. So he starts mentoring Peter more intensively, leading to a closer father - son type of relationship. They could work on new inventions together, with Peter learning a great deal from Tony's experience.
It could be a single, kind - hearted scientist who sees Peter's potential and wants to give him a stable home. The scientist might also be interested in studying Peter's enhanced abilities in a more ethical way compared to some of the villains in the Spider - Man universe.
Well, one possibility is that Harry, who might be in a difficult situation in his own world, is suddenly whisked away to the Marvel universe. Tony Stark, seeing his potential or just feeling a connection, decides to adopt him. Harry could then be introduced to high - tech gadgets and superhero training, and he might use his own magical knowledge in unexpected ways in this new world.
Living with Tony could also make Peter more aware of the bigger picture in the superhero world. He would be exposed to Stark's network of heroes and villains. This could make him more strategic in his actions as Spider - Man. He might start thinking about the long - term consequences of his actions rather than just reacting to immediate threats. For instance, he could start working on ways to prevent crime rather than just stopping it when it happens.
The mentor - mentee relationship. Tony Stark is a genius billionaire playboy philanthropist, and Peter Parker is a young, talented kid with great power. Their pairing is like a dream come true for many fans. Tony can guide Peter in using his powers and technology better.
One possible plot twist could be that Peter's identity as Spider - Man is revealed to the public much earlier than in the original story. Since Tony Stark is his adopted father, he has to use all his resources and influence to protect Peter from the various threats that come with this exposure. This could lead to a lot of interesting scenarios, like Stark having to face off against some of his own business rivals who might want to use Peter's powers for their own gain.