A plot could involve the Avengers trying to understand the concept of alchemy. Maybe Tony Stark becomes really interested in it and tries to incorporate it into his tech. Meanwhile, the Fullmetal Alchemist characters are in awe of the high - tech world of the Avengers. They could end up sharing knowledge and skills to take on a powerful foe that neither could defeat alone. For example, a powerful demon from the Fullmetal Alchemist world that has found a way to use advanced weaponry from the Avengers' world.
A crossover could involve the Homunculi from Fullmetal Alchemist being a threat that the Avengers have to face. The Avengers would be challenged by their unique abilities and the complex nature of the Homunculi. The alchemists might then team up with the Avengers, sharing their knowledge of the Philosopher's Stone and its power, which could be crucial in fighting the Homunculi.
Edward Elric and Tony Stark would definitely have some interesting interactions. Edward, with his knowledge of alchemy, would be both intrigued and a bit put off by Stark's high - tech gadgets. Stark, on the other hand, would probably see Edward as a brilliant but somewhat naive young scientist. They could argue about the best way to solve problems, with Edward pushing for more 'natural' alchemical solutions and Stark relying on his tech.
One idea could be that Naruto somehow ends up in the world of Fullmetal Alchemist and his chakra-based attacks are mistaken for some form of alchemical explosions. For example, his Rasengan could be seen as a condensed form of alchemical energy that explodes on impact.
One popular character is Scar. His unique brand of alchemy and his backstory of revenge can create some really intense crossovers. Edward Elric, as mentioned before, is always popular. He can be paired with characters from other series to have some amazing adventures. Hohenheim is also a character that shows up in a lot of crossovers. His long life and his connection to the Homunculus can add a lot of depth to crossover stories. He can interact with other powerful or long - lived characters from different universes in very engaging ways.
One interesting concept could be the combination of different alchemical abilities from various characters in different universes. For example, if a character from another anime with a unique power system crosses over into the Fullmetal Alchemist world, it could lead to new alchemical reactions and techniques. Another concept might be the exploration of how different cultures and moral codes interact. Characters from different fictional worlds might have different views on equivalent exchange, which could create some really thought - provoking scenarios. Also, the idea of crossovers can introduce new relationships between characters. Characters who have never met before might form alliances or rivalries based on their own goals and personalities.
One great 'Fullmetal Alchemist Scar Crossover Fanfic' is 'Scar's New Path'. It takes Scar on an adventure where he teams up with characters from another universe. The story is really engaging as it delves into Scar's character development in this new and strange setting.
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.
You can start by looking on fanfiction websites like Archive of Our Own (AO3). It has a large collection of fanfictions, and you can search specifically for Fullmetal Alchemist Scar crossovers. Just use the search bar and type in relevant keywords. Another option is FanFiction.net, which also has a wide range of fan - created stories.
One popular theme is the exploration of Greed's complex character in the crossover setting. Since he has his own unique set of desires and moral ambiguities, it often leads to interesting storylines where he interacts with other characters from different universes or story arcs within the Fullmetal Alchemist world. Another theme could be the power dynamics. How does Greed's power compare and interact with the powers of characters from the crossover? It can create some intense battle or cooperation scenarios. Also, the theme of redemption sometimes shows up. As Greed is a character with a lot of 'greed' (obviously), his journey towards possible redemption or further fall into his vices can be a fascinating plot point in fanfictions.