Edward Elric from Fullmetal Alchemist would probably be very curious about the unique abilities in RWBY, like semblances. He might try to study them from an alchemical perspective. Ruby, on the other hand, would likely be in awe of Edward's alchemy skills and his mechanical arm and leg. She could see him as a kind of mentor in a way.
The characters' abilities can interact in really cool ways. For instance, Naruto's Shadow Clone Jutsu could be used in alchemical experiments. He could send clones to gather materials or perform different steps of an alchemical process simultaneously. In return, Edward's alchemy could be used to create structures that are useful for ninja battles, like creating instant fortifications or traps.
One interesting plot twist could be the alchemy of the Fullmetal Alchemist world interacting with the Dust in RWBY. For example, maybe an alchemist discovers a way to transmute Dust into something completely new and unexpected, which throws the balance of power in Remnant (RWBY's world) into chaos. Another could be a character from RWBY somehow getting involved in the Philosopher's Stone plot of Fullmetal Alchemist, leading to a race between different factions in both worlds to either obtain or destroy it.
If Naruto was in the Fullmetal Alchemist world, he would likely interact with Edward Elric in an interesting way. Edward, being a determined and hot - headed character, might be initially skeptical of Naruto. But Naruto's positive attitude and never - give - up spirit could win him over. They could learn from each other's fighting styles. Naruto could show Edward some of his ninja techniques, like the Rasengan, and Edward could teach Naruto about alchemy.
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.
Some characters might be quite shocked or amused if they could read fanfiction about their own story. For example, Edward Elric would probably be very indignant at some of the out - of - character portrayals of himself. He's a proud alchemist and seeing himself depicted in a way that doesn't match his self - image would surely make him fume.
Let's start with Naruto's ability to control the Nine - Tails' chakra. In a crossover, this could be related to the power of the Philosopher's Stone in Fullmetal Alchemist. Maybe the Nine - Tails' chakra has some alchemical properties that can be harnessed. Edward could study this and find a way to use it in his alchemy. On the other hand, the alchemical transmutation circles could be used as a form of jutsu in Naruto. The ninja could draw these circles on the ground or on their bodies to activate different powers. For example, Rock Lee, who doesn't have natural chakra control, could use alchemical transmutation to enhance his physical abilities. He could transmute his muscles to be stronger or more elastic. And for the Homunculi, they could use their immortality to outlast the ninja in long - term battles and learn their techniques over time.
The alchemists' ability to transmute matter could be combined with Pride's shape - shifting abilities. For example, an alchemist could transmute a basic structure, and then Pride could use his powers to shape it into a more complex and efficient form. This would require a lot of cooperation between the characters, which could be interesting to write about.
In some fanfics, characters from other universes might initially be in awe of the Fuhrer due to his power and status. They could approach him with caution, trying to figure out if he's an ally or a threat. For example, a character from a magical universe might be intrigued by the alchemical powers in the Fullmetal Alchemist world and see the Fuhrer as a key to understanding it all.
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 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.