Another reason is the 'forbidden' aspect of their relationship. Envy is a Homunculus, and Ed is a human alchemist. In the world of Fullmetal Alchemist, such a relationship would be frowned upon. But in fanfiction, this taboo nature makes it all the more exciting to explore. It allows writers to break the norms of the original story and create unique and interesting storylines that involve the two characters defying the odds and coming together in different ways.
One great Envy x Ed fanfiction is 'The Unlikely Bond'. It explores how their complex relationship could develop in an alternate universe. The story delves deep into their characters, showing how Envy's envy (pun intended) towards Ed's humanity could turn into something more. It has some really interesting dialogue that stays true to their personalities from the original series.
One possible aspect to consider in this fanfiction could be the character development of ED and AL. Their relationship in the original series is very deep and in the fanfiction, it might explore new dimensions of their bond, perhaps in different scenarios or alternate universes.
There are many fanfictions where Ed is portrayed as a girl. Fanfiction writers like to play with the existing characters in new ways. By making Ed a girl, they can introduce new themes and perspectives. For example, it could change how the story deals with gender roles in the world of Fullmetal Alchemist. Also, it can create new emotional arcs for the character, as a female Ed might face different challenges and experiences compared to the male version in the original story.
One popular theme is the exploration of their different worlds. Ed from his alchemist - filled world and Rose from her more ordinary, yet war - torn world. Their relationship can be a way to bridge these two very different existences. Another theme is sacrifice. In the context of the 'Fullmetal Alchemist' universe, both characters have had to make sacrifices, and in fanfiction, this can be explored further in relation to their relationship. Also, the theme of redemption often comes up. Rose has seen a lot of pain and suffering, and Ed, with his quest for the Philosopher's Stone, might see his actions as a way to redeem himself in her eyes and the eyes of the world.
In a fanfiction, perhaps there's a misunderstanding between Ed and Winry. Winry thinks Ed has feelings for another girl because he's been spending a lot of time with a female alchemist. Ed is oblivious to Winry's concerns at first, but when he realizes, he has to find a way to prove to Winry that she's the only one for him.
One popular theme is the exploration of Envy's complex personality in the crossover. Since Envy is a homunculus with deep - seated issues like envy (obviously), in a crossover, it could be interesting to see how that plays out against new characters or new settings from the other fandom. Another theme could be the struggle for power. Envy often desires power in the Fullmetal Alchemist universe, and in a crossover, this could be magnified or redirected depending on the nature of the crossover. Also, themes of redemption are possible. Despite being a villain, Envy has moments of self - realization, and a crossover could explore if and how Envy could be redeemed in a different fictional context.
In a fanfiction, Ed and Winry could go on a journey together. Maybe they're searching for a rare automail part that could enhance Ed's current prosthetic. Along the way, they face many challenges. They rely on each other's skills - Ed's alchemy and Winry's mechanical knowledge. Their relationship deepens during this adventure as they learn more about each other's dreams and fears.
The complex relationship between Roy and Ed in the original series. Roy is a military man with his own goals and Ed is a young alchemist with a strong will. Their interactions, which can be seen as a mix of rivalry and mutual respect, are interesting to explore in a romantic or more intimate context in yaoi fanfictions.
Another theme is adventure. They go on various quests together in the 'Fullmetal Alchemist' universe. Maybe they are searching for a way to reverse the results of a forbidden alchemy or to stop an evil alchemist. During these adventures, their bond strengthens. In some fanfictions, they face life - threatening situations which make them realize how much they mean to each other.
The fanfiction might introduce new storylines that are not in the original series. It could be something as simple as a day in their lives that was never shown before, or a more complex plot involving new villains or challenges. And seeing how ED and AL react to these new elements is part of the allure.