One common theme is the resolution of their differences. Since they had major conflicts in the movies, fanfic might use a kiss as a way to show them making up. Another theme could be the exploration of a hidden or suppressed love. Maybe in the story, they realize they have deeper feelings for each other that they've been ignoring.
There is a fanfic named 'Cap and Iron Man: United Front'. In this, they team up against a new and powerful enemy that threatens the whole world. It's full of action scenes and also some heart - to - heart conversations between them that are really well - written.
One common theme is redemption. After their big fallout, many fanfics focus on how they can redeem themselves in each other's eyes. For example, they might save each other from dangerous situations.
In the comics, Iron Man did not kill Captain America. Their conflicts and battles were part of the storylines, but not to the extent of one killing the other. The relationship between them was complex but not fatal.
In the comics, Iron Man doesn't end up killing Captain America. Their battles and disputes have various outcomes, but not one that involves a fatal blow from Iron Man.
Yes, it is quite a popular trope in some parts of the fandom. Some fans enjoy exploring the deep bond between Captain America and Iron Man in this way, seeing it as an expression of their strong friendship or a different kind of relationship. It often shows up in fan - created works, including fanfics and fan art.
One possible storyline could be them realizing their deep emotional connection during a particularly tough battle. They start to rely on each other more than just as comrades, and slowly feelings of love and attraction develop. For example, Iron Man might be injured and Captain America stays by his side constantly, leading to a new level of closeness.
In the world of fanfiction, the idea of Iron Man killing Captain America can be quite controversial. Ethically, it goes against the typical heroic and friendly relationship they have in the mainstream Marvel universe. However, fanfiction is a space for exploring different scenarios, so while it may seem unethical to some, it can be a creative exploration for others.