Well, it could also lead to a rescue mission. The Avengers or other superheroes might find out about Peter's kidnapping. They would then come together to form a plan to rescue him. This could involve a lot of strategizing and fighting against Thanos' forces.
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.
Peter would probably be scared at first. He's just a kid, after all, and being kidnapped by a powerful being like Thanos is terrifying. But he would also be defiant. He has a strong sense of responsibility, so he might try to find a way to escape on his own.
Well, one possibility is that Spider - Man's friends, like Ned and MJ, would quickly realize he's missing. They might start their own investigation, using Ned's tech - savvy skills to try and track Peter. Maybe they'd find some clues that lead them to one of Osborn's secret lairs. Another thing could be that Peter manages to break free on his own using his spider - powers and his wits. He could then turn the tables on Osborn and expose his evil plans to the public.
Well, one possibility is that the Avengers will quickly notice Peter's disappearance. Tony Stark might use his high - tech resources to track him down. He could analyze any evidence left behind at the scene of the kidnapping. For example, if Peter's Spider - Man suit has some sort of tracking device, even if Hydra tried to disable it, Stark could find a way to reactivate it or use its last known location to start the search.
Peter might be kidnapped while he's on his way to help someone. Beck could disguise the kidnapping as part of a bigger emergency. Then, Peter would be locked in a place where his powers are restricted in some way. For example, Beck could have some kind of electromagnetic field that dampens Peter's spider - sense.
Another thing that could occur is that the public's perception of him would change drastically. Some might see him as a hero, but others could fear him or be angry that he's been hiding his identity all this time. There could be protests or demands for him to be regulated in some way.
Well, Tony might get angry at first. He's used to being in control and having his orders followed. But then he could also realize that Peter has a point. Maybe they would have a big argument that leads to Peter leaving the team or Tony having to re - evaluate his plans.
Perhaps in this fanfiction, Peter has some new power or gadget that he's testing. So when he jumps off the building, instead of the usual web - swinging, he activates this new ability which allows him to fly or at least glide to the ground in a very cool and unexpected way.
In a fanfiction scenario, it's also likely that he discovers a new community of omega superheroes or mutants. This new community could teach him about his omega nature, its strengths and weaknesses. They could also help him develop new skills or powers that are unique to omegas, which would then help him in his fight against evil.
One possible plot could be that Peter Parker discovers a new power within himself that gives him the edge to take on Thanos. Maybe it's a power related to the Time Stone that he manages to manipulate in a way that Thanos can't counter. He could use this power to outwit Thanos in a battle and finally deliver the killing blow.