Another concept is the exploration of different worlds within One Piece. If an admiral crosses over to a less - known or mysterious island, it can open up new storylines. Maybe they discover ancient secrets or new types of Devil Fruits. This can bring a fresh perspective to the One Piece universe as a whole.
Well, the character development is a big part. In these crossovers, admirals might find themselves in situations that force them to change their views. Like if they are paired with a more morally gray character from another part of the One Piece world. They could start to question their strict sense of justice. This adds a whole new layer to their personalities.
One interesting concept is a crossover with other popular anime like Naruto. Imagine Luffy and Naruto teaming up, it would be a clash of two very different power systems and personalities. Another concept could be a crossover with a superhero universe. For example, Luffy meeting Superman. Their powers are so different, it would make for an exciting story.
Aokiji is popular too. His more laid - back approach to justice compared to Akainu makes him a great character for crossovers. He can form interesting relationships with other characters, and his ice - based powers can be used in creative ways in different crossover scenarios.
Well, a really cool concept is the idea of One Piece pirates learning magic. Imagine Zoro trying to master spells instead of sword techniques. It would be a hilarious and interesting twist. Also, the idea of Hogwarts students being interested in the One Piece world and its treasures. They might see the One Piece as a sort of ultimate magical artifact that they want to discover.
You could also explore an OC Admiral who is a bit of an outlier in the Navy. Maybe they have a more lenient view on pirates and believe in reform rather than just punishment. This would create a lot of internal conflict within the Navy and interesting interactions with the Straw Hat crew when they cross paths.
One interesting concept is alternate universe stories. For example, what if Luffy didn't eat the Gum - Gum Fruit but a different Devil Fruit? Another concept could be character backstories that are expanded or changed. Maybe a fanfic delves deeper into Sanji's time at the Baratie and creates new relationships or events during that period. Also, there are fanfictions that explore different power - up scenarios for the characters, like if Zoro found a new type of sword with unique abilities.
One interesting concept could be Shreck crossing over with other fairytale characters in a modern setting. For example, Shreck meeting characters from 'Cinderella' in a bustling city. It can create humorous and unexpected interactions, like Shreck's gruff nature clashing with Cinderella's elegance.
One interesting concept could be the combination of Ben 10 000's powers with other fictional universes. For example, if he were to cross over with the DC universe, seeing how his alien forms interact with super - heroes like Superman or Batman. Maybe his Four Arms form could have an epic battle with Doomsday.
Well, a lot of fgo crossover fanfiction involves different historical periods colliding. Say, a crossover with the Roman Empire era and the modern day in the fgo world. Servants from different eras teaming up or facing off against each other can create really engaging storylines. Also, crossovers with other JRPGs like 'Final Fantasy' often bring in unique magic systems and character designs that add a whole new dimension to the fgo fanfiction.
Another concept might be a crossover with a superhero universe. Picture the Metalocalypse band members having to deal with superheroes and villains. They could use their music in unexpected ways, like using a powerful guitar solo to stun villains or inspire superheroes in battle.
A third concept could be a crossover with a historical era. Picture Kidomaro in ancient Rome or medieval Europe. He would have to deal with the social norms, different forms of combat, and the overall culture of that time period. This would likely lead to some very unique and engaging storylines as he tries to find his place in a world so different from his own.