A possible scenario is that the Soul Stone has a connection to Tony Stark's past. Maybe it was involved in an experiment that his father was part of long ago. When Tony discovers this link, he becomes determined to understand the Soul Stone better. He starts to study it, and as he does, he finds that it has the power to manipulate emotions on a grand scale. This could either be a great weapon in his fight against villains or a dangerous tool that could turn his friends against each other if not used carefully. And throughout this process, Tony Stark has to constantly battle his own demons and desires as he interacts with the Soul Stone.
In fanfiction, Tony Stark may be linked to the Soul Stone in a way that it affects his character arc. The Soul Stone could represent a temptation for him. Given his complex personality, the power of the Soul Stone might either corrupt him or make him a better hero. It could also be that he is the only one who can resist the dark side of the Soul Stone's power, and this makes him a crucial figure in the fanfiction's plot related to the stone.
One scenario could be that he is locked out of his own workshop by some sort of malfunction or enemy interference. He then uses his lock - picking skills to get back in and resume his work on an important project. Another possibility is that he needs to break into a Hydra facility to steal some crucial data, and lock - picking is the quietest way to gain access.
Maybe Peter misses an important training session. Tony has probably put a lot of effort into training Peter to be a better superhero. If Peter skips out on training for something unimportant, like going to a party or just being lazy, Tony would be justifiably angry and yell at him for not taking his superhero responsibilities seriously.
One possible situation in this fanfiction could be that Tony Stark tries to show off with his high - tech gadgets during the first date, but it backfires. For example, he might bring out some newfangled device that malfunctions and causes chaos. Also, his playboy reputation might precede him, and the date might be put off by his past dalliances. Or he could be so focused on saving the world that he seems distracted and uninterested in the date.
One scenario could be after Peter has a particularly bad day at school. He gets bullied or fails a test, and he goes to Tony feeling down. Tony sits him down and tells him that grades and what bullies think don't define him. He might even offer to get Peter a tutor or deal with the bullies in a non - violent but effective way.
Yes, there might be such a fanfiction out there. Fanfiction often explores dark and alternative storylines. However, it can be quite a controversial and dark concept as Tony and Peter have a mentor - mentee relationship in the mainstream Marvel stories.
Maybe in the fanfiction's universe, the rules for obtaining the Soul Stone are different. It could be that the Stone demands a sacrifice of someone with a pure heart like Peter, and Tony, in his desperation to stop an even greater evil, makes the ultimate sacrifice. Another reason could be that Tony is being manipulated by some dark force. This force convinces him that killing Peter for the Soul Stone is the right thing to do, and Tony, believing he is doing the greater good, goes through with it.
Another scenario could involve soul resonance gone wrong. In the 'Soul Eater' world, soul resonance is crucial. In fanfiction, perhaps two characters attempt a very powerful and untested form of soul resonance. But due to a lack of proper understanding or some external interference, it backfires. This could lead to the souls of the characters involved getting hurt. Like if Soul and Maka tried a new level of resonance without fully preparing, their souls might experience a shock that causes internal pain and disrupts their connection.
One scenario could be when the Avengers accidentally damage his technology. Tony Stark is very attached to his inventions, and if, for instance, Thor's hammer smashes one of his high - tech gadgets during a battle, he might get angry at the Avengers for not being more careful. His anger would stem from the fact that he spent a lot of time and resources creating those things.
One interesting scenario could be Tony Stark using his superior intellect to outwit Thanos in a battle of wits rather than just brute force. He might create a device that can nullify the power of the Infinity Stones for a short time.