His relationship with Pepper could be strained. Pepper might be worried about his health both physically and mentally. She could try to encourage him to lead a healthier lifestyle, which might lead to some arguments as Tony is used to his own ways.
Her relationships with her friends might change. Some friends could be worried about her sudden weight gain and try to help in their own ways. For instance, they might offer to train with her more often.
Another idea could be that Tony is exposed to some sort of experimental technology that has an unexpected side effect on his metabolism, causing him to gain weight. He then has to race against time to find a way to reverse it while also dealing with the media frenzy and public perception of Iron Man not looking as 'fit' as he used to be.
It can make his relationships more intense. For example, Pepper might be even more protective of him, constantly worried about his health. Their relationship could have more tender and worried moments.
Maybe he doesn't fully understand his powers yet. Tony Stark is a scientific genius, but new powers might be beyond his current understanding. He could be worried that if he reveals them too soon, he won't be able to control them properly and might cause harm. So, he chooses to hide them while he studies and figures them out.
Her relationship with Sasuke could be affected. Sasuke might be initially surprised by her physical change. But if he truly loves her, he would look past it. He could support her in her journey of self - acceptance and they could grow closer as he helps her deal with any difficulties that come with the weight gain.
It could strengthen her relationship with Harry. Harry, being a true friend and lover, would support Ginny through her change and show that his love is not based on appearance. This would deepen their bond.
Pepper Potts could be a big help. She knows Tony so well, and she could try to jog his memory by showing him things from their past together, like pictures or mementos. Rhodey could also be there for him. He could tell Tony stories about their military days and how they became friends, which might trigger some memories.
Tony would be a protective father. He'd raise the child in an environment full of knowledge. He'd introduce the child to his friends like Pepper, Rhodey, and the Avengers. The child would grow up hearing stories of heroism and would be inspired to be a good person. Tony would also use his wealth to give the child the best education possible, but also let the child explore their own interests. For example, if the child showed an interest in art, Tony would support that as well as their scientific pursuits.
A group of disgruntled former Stark Industries employees could become his sidekicks. They feel betrayed by Tony in some way, maybe due to layoffs or unfulfilled promises. So when he turns villain, they join him, using their skills to help him carry out his evil plans, like sabotaging other tech companies or stealing their research.
Naruto might combine his Rasengan technique with Stark's arc reactor concept. Imagine a Rasengan that has a self - sustaining energy core like the arc reactor, making it more powerful and long - lasting. This would require Naruto to understand some of Stark's engineering principles, which he could learn from books or by observing Stark's technology in the fanfiction. He could also use his ninja speed and stealth to protect Stark's technology from villains in the story who might want to steal it.