Well, a plot could involve Edward being betrayed by a mentor figure. This person could have been guiding him in alchemy all along but has a hidden agenda. Maybe they want to use Edward's unique alchemical abilities for their own dark experiments. Or, in a different scenario, Edward could be betrayed by a love interest. She might pretend to love him while actually spying on him for an opposing force, stealing his secrets and leaving him heartbroken and in a difficult situation.
In some fanfictions, Edward might be betrayed by the very people he is trying to save. For example, the citizens of a town he is helping could turn against him due to false rumors spread by an enemy. They could believe that Edward is causing more harm than good. Another possibility is that a fellow alchemist, whom Edward thought was an equal and a friend, betrays him in order to be the sole possessor of a rare alchemical discovery. This could lead to a battle of wits and alchemy between them.
Well, perhaps in the fanfiction, Edward is kidnapped by a secret organization that wants to use his knowledge of the military's alchemical operations. They might hold him captive in an underground lair, filled with strange alchemical contraptions. Or maybe he's kidnapped by a jealous alchemist who feels overshadowed by Edward's fame. This alchemist could try to steal Edward's research and take credit for his work. Also, it could be that an otherworldly being kidnaps him to learn about human alchemy.
Well, perhaps in the fanfiction, Edward's sacrifice causes a rift in the fabric of time. This rift then starts to distort reality, and it's up to his friends to figure out how to fix it. They have to journey through different time periods and face challenges that Edward had faced before. Or it could be that his sacrifice was misinterpreted by some, and they start to view alchemy as a dangerous art again, leading to a conflict between those who understand the true meaning of Edward's sacrifice and those who don't.
A crossover with the world of Attack on Titan could be interesting. Female Edward could use her alchemy to help in the fight against the Titans. Maybe she could create new weapons or defenses using her alchemical knowledge. And her relationship with the Survey Corps members would be a great source of character development.
A really interesting plot could be a time - travel scenario. Chimera Mustang and Edward Elric get sent back in time to a crucial point in the history of alchemy. They have to navigate this new - old world while also trying not to change history too much. This would be full of opportunities for them to interact with past versions of characters and maybe even prevent some future disasters.
In this fanfiction, her role as an alchemist might be perceived differently. As a girl, she might face more discrimination in the male - dominated field of alchemy. This could lead to stories of her having to prove herself more often and in different ways than in the original story.
One idea could be a crossover where Edward and Urahara meet in a world that combines their respective universes. They could exchange knowledge about alchemy and spiritual powers. For example, Edward could be intrigued by Urahara's zanpakuto and its unique abilities, while Urahara might be interested in the principles of alchemy.
One interesting plot idea could be that Roy and Edward have to team up on a secret mission that involves alchemy and military strategy. They start off not getting along well because of their different personalities and approaches, but as the mission progresses, they learn to respect each other and become friends. Another idea is that Edward discovers a new form of alchemy that Roy is interested in for military use, and they have to work together to keep it from falling into the wrong hands.
Well, a plot could involve Hermione being influenced by a powerful dark magic item. This item warps her mind and makes her see Harry as a threat to the wizarding world. So, she betrays him by revealing his secrets to his enemies. Or perhaps she gets jealous of Harry's popularity and power and that leads to her betrayal in a moment of weakness.
Well, perhaps in the fanfiction, Bella discovers some unique powers during her pregnancy that are related to the kingdom's magic. And King Edward has to protect her from those who might want to use her and the baby for their own gain. Also, they could have a series of adventures together as they prepare for the arrival of their baby, like exploring ancient ruins to find baby - related artifacts.
One great fanfiction could be 'The Road to Recovery'. In this, Edward's injury is not just physical but also psychological. The author delves deep into how he copes with the pain and his journey to regain his strength. Another one is 'Injured but Unbroken' which focuses on his relationships with his friends and how they support him during his time of injury.