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.
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.
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.
Perhaps Edward and Urahara would have an interesting dynamic in combat. Edward's quick - thinking and ability to transmute objects on the fly could be a great complement to Urahara's zanpakuto skills and his use of various spiritual items. They could learn from each other's fighting styles and develop new techniques together. Urahara might also introduce Edward to some of the other characters in the Bleach universe, like Orihime and Chad, and Edward could share stories about his friends in Amestris.
One great 'Angel Edward Elric' fanfiction is 'The Celestial Alchemist'. It has a really interesting plot where Edward discovers his angelic powers and has to use them to save his world from a dark force. The character development is well - done and it stays true to the original 'Fullmetal Alchemist' vibe.
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.
At first, Edward might be a bit resistant to Roy's attempts at adoption. But as time goes on, Roy shows his care and concern for Edward. He helps Edward with his problems, like dealing with the homunculi or his own self - doubt. Edward then starts to rely on Roy more, and their relationship deepens into a strong bond of family - like love.
Another theme could be innocence. Baby Edward is in a pure state, and fanfictions might explore how this innocence is gradually lost as he grows up and faces the hardships of the alchemical world. For example, a story could show how his first encounter with the darker side of alchemy starts to chip away at his innocent view of the world. It could be something as simple as seeing an alchemical experiment go wrong and realizing that there are consequences to the power he's so interested in.
They could start by comparing their different worlds. Edward would explain about the principles of alchemy like equivalent exchange, while Urahara would talk about the Soul Society and the way spiritual power works. This exchange of knowledge could be the foundation for their relationship in the fanfiction.
One common theme is the struggle with identity. Since Edward becomes a chimera, he has to deal with not only his physical changes but also how it affects his sense of self.