Ben 10 is a favorite for many. As I said before, the clash between Johnny's human - centered confidence and Ben's alien - powered abilities is exciting. Also, characters like Dexter from Dexter's Laboratory are often used. The scientific genius of Dexter and the not - so - smart Johnny can lead to hilarious and complex stories. Courage the Cowardly Dog is also a great choice as the spooky and strange world Courage lives in can be a great backdrop for Johnny's adventures.
Fiona is also a top choice. Her relationship with Shreck in the movies gives a lot of material for crossovers. Fanfiction writers might explore how she and Shreck interact in different universes or scenarios, like in a world where they are not in the same fairytale but a different, more modern world.
Sherlock Holmes is also quite popular. Holmes' deductive skills against Darth Vader's power in the Force would make for an exciting story. Holmes could be trying to figure out Vader's motives and secrets, while Vader might see Holmes as a nuisance or a potential ally depending on the situation.
Definitely Bell Cranel. If he is crossed over into the Naruto world, his growth as an adventurer in Danmachi can be compared to the growth of a ninja in Naruto. His determination to become stronger is similar to Naruto's. Also, Ais Wallenstein is popular. Her combat skills and beauty would make for an interesting combination in the Naruto universe, perhaps having epic battles with Naruto's strong female characters like Tsunade.
Thor is often crossed over with the Hulk. They already have a history in the official comics with their epic battles. In fanfiction, it could be about them teaming up more often or having to face a threat that only their combined powers can defeat, like a powerful cosmic entity.
Definitely Iron Man. Their relationship in the official Marvel movies has already been very popular, so in fanfiction, writers love to explore more of their interactions. Iron Man can provide high - tech support to Spider - Man, and they can have some really smart and witty conversations.
In the world of fanfiction, these two characters are central. Johnny Bravo's attempts to be the hero or the coolest guy around are often thwarted by Little Suzy's intelligence and straightforwardness. Their relationship can range from a sort of big - brother - little - sister dynamic to being partners in some wacky adventures.
Obviously, Johnny Bravo is one of the main characters. And the girls, who are now depicted as smart, are also main characters. But without reading the specific fanfiction, it's hard to say exactly which girls are focused on. It could be the regular female characters from the original show who are given a new smart - girl makeover.
Definitely Ultraman. He is a well - known Japanese superhero, and when combined with Godzilla in fanfic, it creates a great mix of super - powered action. Also, Gamera is often crossed over with Godzilla. They are both giant turtle - like monsters in their own rights, and the crossovers usually involve some intense battles over who is the more powerful or dominant one.
Aquaman himself is often a popular choice. His unique abilities and his role as a king make him an interesting character to insert into the Game of Thrones universe. He could potentially interact with various characters in Westeros.
In Naruto - Scott Pilgrim fanfiction, Rock Lee is a character that many fans like to cross over. His unique fighting style based on pure hard work and determination would be really cool to see in the Scott Pilgrim universe. And from Scott Pilgrim's side, Wallace Wells could be a popular crossover character. His laid - back and sarcastic personality could create some humorous moments when interacting with the Naruto characters.