One idea could be a story where Athos, Porthos, and Aramis go on a secret mission together. They face many challenges and have to use their unique skills to overcome them. For example, Athos' calm leadership, Porthos' strength, and Aramis' charm and intelligence all play a part in the success of the mission.
A great plot twist could be that one of them is secretly working for the enemy all along. For instance, it seems like Athos is on their side, but then it's revealed that he has been manipulated into helping the opposing force. This would shatter the trust within the group.
The theme of honor is quite prevalent. They are musketeers, and fan fictions uphold their sense of honor. They will not break their word or act in a dishonorable way. Moreover, the theme of sacrifice also exists. There are times when one of them has to sacrifice something for the sake of the other or for the greater good, like giving up a chance for personal glory to save a friend.
Friendship is a very common theme. D'Artagnan and Athos have a deep bond in the original work, and fan fictions often explore this further. Another theme is adventure. They are characters known for their exciting escapades, and fan fictions build on this. Honor is also frequently explored as both characters uphold a certain code of honor.
Aramis could choose to confront Athos directly. He might say something like 'Athos, what you did really hurt me. I don't understand why you would say such things.' This way, he gives Athos a chance to explain himself and they can start to resolve the issue.
One great piece of d'artagnan athos fan fiction is 'The Bond of Brothers'. It really delves into their relationship, showing how their loyalty to each other grows through various challenges. Another is 'The Unseen Adventures', which takes them on a quest that isn't in the original stories, highlighting their individual strengths and how they complement each other.
One popular piece of 'd'artagnan athos 1993 fan fiction' might be 'The Adventures of D'Artagnan and Athos: A Reimagined Bond'. It delves deeper into their friendship and the challenges they face together. Another could be 'D'Artagnan and Athos: Against All Odds' which focuses on their adventures in a more action - packed way. There are also some that explore their backstories, like 'The Origins of D'Artagnan and Athos' which gives a detailed account of how they became the characters we know.
Maybe Athos is jealous of Aramis. For example, if Aramis gets more attention from a certain person they both care about, like a mutual friend or a love interest. This jealousy could lead him to say or do things that unintentionally or even intentionally hurt Aramis's feelings.
You can find athos aramis fanfic on some popular fanfiction websites like Archive of Our Own (AO3). It has a large collection of fanfics related to various fandoms, including the Musketeers, where you can easily search for athos aramis fanfic.