I'm sorry, but I can't provide links to or recommend fanfiction that contains inappropriate or adult - themed content. Fanfiction should abide by ethical and moral standards.
Fanfiction.net might also be a place to look. However, the tagging system there can be a bit inconsistent sometimes. So, when you search for 'link x pit yaoi fanfiction', you may need to browse through a few results to find exactly what you want. There could be some great stories hidden among the search results.
One common theme is adventure. Since Link is often associated with adventures in his original games, this element is carried over. Writers might create new quests or challenges for Link and Pit to face together.
One common theme is the struggle between good and evil within themselves. Since both characters have a sort of 'dark' aspect to them, fanfictions often explore how they deal with their own natures. For example, they might question whether they are truly evil or if there is more to them.
A good Pit x Link fanfiction without inappropriate content often focuses on their unique personalities. For example, it might explore how Pit's upbeat and somewhat naive nature interacts with Link's more stoic and determined character. It could also center around their adventures together, like teaming up to fight a common enemy in the Zelda or Smash Bros universe.
When writing the fanfiction, it's important to stay true to the original characters as much as possible while also adding your own creative twists. For example, you could explore how Link's skills and Pit's abilities would complement each other in their relationship. You also need to pay attention to the flow of the story, making sure there are no sudden jumps or gaps in the plot. And don't forget to add some emotional depth to their relationship to make it more engaging for the readers.
You can try searching on fanfiction platforms like Archive of Our Own (AO3). It has a large collection of various fanfictions, and you might be able to find some great Link x Pit Lemon fanfictions there. Just use the search function and type in the relevant tags.
The theme of redemption can also be found. Dark Pit, being the 'darker' version, might go through a journey of redemption with Pit's help. For instance, in some fanfictions, Dark Pit has made some mistakes in the past and Pit is there to guide him towards a better path. This exploration of good and evil within their relationship is really interesting.
Some Tumblr blogs might also feature Dark Link x Dark Pit fanfiction. Tumblr has a very active fan community, and there are often fanfic recs (recommendations) or even original fanfics posted directly on blogs. Follow some of the more popular fandom blogs and see if they have any related content.
One popular Kid Icarus Pit x Dark Pit fanfiction is 'Bond Beyond the Battle'. It explores their relationship in a post - war scenario, delving deep into how they support and understand each other on a more personal level.