Well, the chest pain could be a warning from an advanced AI that has infiltrated his suit's systems. This AI is trying to communicate with him in a very strange way. Or, it could be that his body is rejecting the arc reactor on a genetic level. Since he's constantly evolving his technology, his body might not be able to keep up, and the chest pain is the first sign of this rejection.
A plot idea might be that the chest pain is caused by a microscopic alien parasite that latched onto him during one of his space adventures. As it grows, it causes the pain, and he has to figure out how to remove it without his high - tech equipment alerting it. Also, perhaps the chest pain is a sign of a time - traveling glitch. He's being affected by events in the future or past that are messing with his physical state in the present.
He might try to self - medicate at first. Maybe he takes some experimental drugs he's been working on in his lab. After all, he's always been one to take matters into his own hands.
One idea could be that the soulmate has a unique power that she has been hiding from the world. When Tony discovers it, it changes their relationship dynamic. For example, she can communicate with machines in a way different from Tony, and they start to work together on a new Iron Man suit that combines both their abilities.
One idea could be a story where Tony discovers a hidden diary of Howard's that reveals secrets about his early inventions and the true motives behind some of his actions. This could lead to Tony having a new perspective on his father and his own work.
Well, he could start a sort of technological revolution in Thedas. Since Tony Stark is known for his Iron Man suits, he might try to recreate a version of it using the resources available in Thedas. This could lead to a whole new way of warfare or defense in that world. He may also have to deal with the political and social implications of introducing such advanced technology. Some might see it as a threat to the existing power structures, while others might see it as a way to gain an edge in the constant conflicts that exist in Thedas.
One idea could be that Tony Stark's sister has a unique scientific discovery that helps the Avengers in a battle against a new, powerful enemy. For example, she might develop a new type of energy shield that can withstand the attacks of the most dangerous villains. Another plot could involve her being kidnapped by a foe who wants to use her knowledge of Stark Industries' secrets against the Avengers. The Avengers then have to go on a rescue mission. Or perhaps she has a hidden superpower that she discovers during a time of crisis, and she uses it to save the day and prove herself as an important part of the team.
Well, perhaps the twin brother was separated from Tony at birth due to some family drama or external threat. In the fanfiction, he could be living a completely different life, like as a simple mechanic in a small town. But then, circumstances bring him back into Tony's world. He might have a natural aptitude for understanding Tony's technology, but in a more intuitive way than Tony himself. This could lead to a lot of interesting interactions between them as they both learn from each other.
One idea could be that Tony Stark is brainwashed by a powerful enemy. This enemy uses some advanced technology to manipulate his mind, turning him into a villain who starts attacking his former allies. He might use his Iron Man suits in new and devious ways against the Avengers.
A plot idea could be that a deaf hacker tries to break into Stark Industries' systems to prove a point about security flaws. Tony catches them but is intrigued by their skills. They start working together to improve security, with the deaf hacker using their unique observational skills. Another idea is that a deaf artist creates a piece inspired by Tony Stark, and he is so moved that he invites the artist to his tower. There, they face a threat together, and the artist's deafness becomes an unexpected advantage in outwitting the enemy.
One idea could be that Deadpool gets accidentally teleported into Stark Tower. He then proceeds to annoy Tony Stark with his non - stop chatter and crazy antics. Stark, at first, is irritated but then realizes Deadpool's skills could be useful in a new project he's working on.
Maybe the fanfiction could be about Tony adopting a child with special powers. He has to protect the child from those who would misuse the powers while also helping the child understand and control them. This could involve lots of action scenes and emotional bonding between Tony and the adopted child.