Character growth is also very important. As Edward experiences different time periods, he learns new things and his perspective changes. He might start off thinking he can fix everything with his alchemy knowledge, but then realize that some things are more complex than that. It's about him evolving as a character throughout his time - traveling journey.
One key element is the alteration of the timeline. Since Edward travels through time, the changes he makes or tries to make can have a huge impact on the events that are supposed to happen. For example, he might try to save someone who was supposed to die, which could then change the whole course of the story.
Love and sacrifice are also important. Since their relationship is not always easy due to their different lives. There are often moments where one has to sacrifice something for the other, whether it's Edward sacrificing his time with alchemy research to be with Rose or Rose sacrificing her own safety to help Edward in his dangerous adventures.
One great Edward Elric time travel fanfiction is 'A Time - Twisted Alchemy'. In this story, Edward travels back in time and tries to prevent some of the tragedies that befell his family. It has really interesting character development and explores how his knowledge of the future could change things.
Edward might meet his parents. Since he has the chance to go back in time, he could meet them when they were alive and perhaps learn more about alchemy from them, which could change his future actions.
Yes, there are likely fanfictions out there with such a concept. The worlds of Naruto and Fullmetal Alchemist, where Edward Elric comes from, are quite different, but that's what makes the idea of a crossover in fanfiction so interesting. Writers might explore how Naruto's ninja world and its unique powers could interact with Edward's alchemical abilities and the complex world of Amestris.
Alphonse Elric is often present. He might play a role in helping Edward understand and use his new gamer - like abilities in relation to alchemy. For example, he could be the one who discovers a new aspect of Edward's powers.
In this kind of fanfiction, Edward might try to change the past events that led to his and his brother's misfortunes. Maybe he'd prevent the failed human transmutation in the first place, saving Alphonse from losing his body.
In fanfiction, Edward as a sniper often has a strong sense of purpose. His experiences with alchemy and his quest for the Philosopher's Stone might translate into his sniper role. He might be using his sniper skills to protect something or someone important. Also, his determination would be a big part of his character as a sniper. He'd be willing to wait for the perfect shot, no matter how long it takes. And his intelligence would play a role in strategizing his shots and anticipating his targets' movements.
In fanfiction, the possibilities are nearly endless. Regarding Edward Elric becoming a homunculus, it could be a very interesting concept. If he were to become one, it would completely change his relationship with other characters. For example, his brother Alphonse might react in a very different way. Also, Edward's own view of himself and his abilities would be transformed. His struggle with his new form, if it were to happen, could be a central theme in the fanfiction. Maybe he would try to find a way to reverse the process, or perhaps he would embrace his new existence as a homunculus. It all depends on the creativity of the fanfiction author.
Edward Elric has a more straightforward personality. He wears his emotions on his sleeve. When he's angry, you know it, and when he's happy, he shows it. He's also very sarcastic at times. Edward Cullen is a bit more complex. He's got that mysterious allure because of his vampire status. He's not as open with his emotions as Elric. Cullen is more introspective, always thinking about the consequences of his actions, especially since his actions can have a big impact on the humans around him.
Another theme is redemption. Some fanfictions might explore the idea of whether Pride can be redeemed through its interactions with Edward. It could be a complex exploration of good and evil, where Edward's character might influence Pride to change or at least question its own existence and actions.