Natasha Romanoff would be disappointed. She values the unity among the Avengers and sees Tony and Steve as important pillars of that unity. She might try to mediate at first, but if the divorce is inevitable, she'd be sad to see the team's dynamic change so drastically.
Thor would be rather confused. He comes from Asgard and has a different understanding of relationships. He might not fully comprehend the concept of divorce among men. He'd probably offer some very Asgardian - style advice, like facing the situation with honor and courage, which might not be entirely applicable but still his well - intentioned attempt to help.
One possible plot reason could be ideological differences. Tony Stark is often portrayed as a tech - savvy capitalist, while Steve Rogers has more traditional values. Their views on how to protect the world, like Tony's preference for high - tech solutions and Steve's leaning towards more human - centered approaches, might drive them apart to the point of divorce in the fanfiction.
Natasha would probably be very supportive. She's seen their relationship develop over time and would be happy for them. She might also be the one to help smooth out any bumps in the road during the wedding preparations.
Steve Rogers would probably be deeply disappointed. He values loyalty highly, and Tony's betrayal would shatter the trust they had. He would try to find out the reasons behind it and might even try to bring Tony back to the right path if he thought there was a chance.
Some fans would be extremely shocked and disappointed. Steve and Tony are two beloved characters, and their relationship is complex and interesting. Killing one of them off in such a way would be a huge departure from what many expect.
Tony would probably be extremely hurt. He trusted his team, and betrayal would cut deep. He might initially be in denial, not wanting to believe that his friends could turn on him.
He would probably be overprotective at first. Tony has been through a lot, and the idea of his daughter having mutant powers, which could make her a target, would be scary for him. He might try to keep her locked away in the Stark Tower, but that would likely lead to her rebelling.
The Avengers would be in a state of panic and fury. Captain America would likely lead the charge to find Tony. He'd use his military strategy skills to plan a rescue mission. Thor might use his godly powers to track down any signs of Tony's whereabouts. Black Widow and Hawkeye would be on the lookout for any Hydra agents or informants. Hulk could be a wildcard. He might be uncontrollably angry and ready to smash anything in his path to get to Tony.
He'd probably be shocked at first. Tony is always so caught up in his own world that a secret daughter would be a huge surprise. But then he'd likely be protective. He might try to keep her away from his dangerous life at first, but as he gets to know her, he'd start to include her in things.
One possible reason could be differences in their superhero duties. Maybe their approaches to saving the world clashed so much that it put a strain on their relationship. For example, Tony might be more into high - tech solutions while Steve prefers a more traditional, hands - on approach.
He'd be frantic. Tony loves his daughter deeply, so he'd immediately start searching for her. He'd use all his resources, his technology, and his connections to find her.