It could be Tony. He's always curious and out - going. He might have noticed Bucky at an event or something and decided to approach him just out of sheer interest.
Bucky could also be the instigator. If he heard about Tony Stark and his technological prowess, he might be eager to meet him. Bucky, with his cybernetic arm, might be interested in getting some insights from Tony on how to better manage or even upgrade his prosthetic. So he could seek Tony out at an appropriate place and time to start a conversation.
Well, perhaps they meet at a Stark Industries event. Tony is the owner, so he's there, and Bucky could be there as part of a security detail or just as an attendee. They might start off with a bit of a misunderstanding, Tony being the flamboyant inventor and Bucky the more reserved soldier. But then they find common ground in their shared interest in technology, especially when it comes to Bucky's cybernetic arm. They could exchange ideas about how to improve it or just have a general conversation about the future of technology in warfare and prosthetics.
Maybe a new super - powered villain who has the ability to manipulate minds. They target the meeting because they want to turn the superheroes against each other. Since Bucky has a history of being mind - controlled, he would be especially vulnerable to this villain's powers. So, this villain could be a great antagonist in the fanfiction. They could start by subtly influencing the conversations at the meeting and then escalate to full - on attacks.
One great 'Bucky meets Tony' fanfic could be 'A New Alliance'. In this fanfic, Bucky and Tony are forced to work together on a mission. Their initial distrust slowly turns into mutual respect as they realize they have more in common than they thought, especially in terms of their experiences with trauma and trying to find their place in the new world.
The potential for character development. They both have their own traumas and issues. Fanfic writers can explore how they help each other grow and overcome their problems. For example, Tony could use his technology to help Bucky deal with the Winter Soldier programming, and Bucky could offer Tony a different perspective on life and loyalty.
Another possibility is a new villain who has the power to control Bucky's actions. This villain could be after Tony for his wealth or his influence in the superhero community. The villain forces Bucky to do the dirty work while staying in the shadows.
Well, in this kind of fanfiction, it often explores a different side of the relationship between Bucky and Tony. It might show Bucky using his charm in unique ways. Maybe he starts with some sly compliments or little gestures that are out of the ordinary for their typical dynamic in the original story.
One great 'Bucky x Tony Tony nightmare' fanfiction is 'The Broken Alliance'. It delves deep into the complex relationship between Bucky and Tony. In this story, a nightmare situation forces them to confront their past differences and work together. The character development is really well - done, showing how they grow from being at odds to understanding each other on a deeper level.
The plot could start with Steve realizing that his bond with Bucky is stronger than his relationship with Tony. Maybe there have been some misunderstandings or conflicts between Steve and Tony that make Steve reevaluate his feelings. Then, Steve decides to break things off with Tony in a rather dramatic way. After that, it could explore how Tony reacts to this rejection, and how Bucky fits into the new dynamic between Steve and the rest of the Avengers.
At first, it might be a bit rocky. Tony, being used to his own space, might feel smothered by Steve and Bucky's over - protectiveness. But as time goes on, he'll start to see their good intentions. Steve's moral compass will inspire Tony to be a better person, and Bucky's loyalty will make Tony feel secure. Eventually, they'll become like a real family, with Tony looking up to Steve as a father figure and seeing Bucky as a cool older brother.
One possible plot could be that Bucky, while on a mission in Wakanda, accidentally stumbles upon T'Challa's daughter during her secret training. She's initially cautious but then realizes Bucky is different from what she expected. They start to share stories about their different worlds and form an unlikely friendship.