Another interesting concept is to have the characters from Berserk interact with the magical creatures and races of the kingdom. The Band of the Hawk could be hired as mercenaries by the kingdom to fight off an invasion of some sort. This would lead to some great action scenes and also allow for character development as they interact with the new and different people of the kingdom.
One idea could be a Berserk and Dark Souls crossover. Picture Guts in the dark and unforgiving world of Dark Souls, facing off against the powerful bosses there with his greatsword. His tenacity and fighting skills would make for an exciting addition to the Dark Souls lore.
Maybe Sora, Donald, and Goofy end up in the Naruto universe. They would be really confused at first. Sora could try to understand the concept of chakra and how it's different from the magic he knows. They could team up with Naruto's team to take on Akatsuki members who have somehow been influenced by the darkness in the Kingdom Hearts world.
To make it unique, focus on the character interactions. Don't just have the Berserk characters barge into the kingdom and start fighting. Let them form relationships, both positive and negative, with the kingdom's inhabitants. For instance, a Berserk character might fall in love with a local from the kingdom, which could change their perspective and goals.
Well, a Berserk - Game of Thrones fanfic could focus on the concept of power. In Berserk, Griffith is obsessed with power and in Game of Thrones, many characters are vying for the Iron Throne. A fanfic could explore what would happen if Griffith was transported to Westeros. He would surely see the Iron Throne as a symbol of ultimate power and try to claim it. Or it could be about a character from Game of Thrones, like Tyrion Lannister, who has to deal with the nightmarish creatures of Berserk. He might use his wits to try and find a way to co - exist with them or defeat them.
One idea could be that Guts from Berserk is somehow transported to the Naruto universe. He could encounter Naruto and his friends. Maybe they initially mistake him for an enemy because of his intimidating appearance and weaponry. But as they get to know him, they realize his noble heart and his fight against the forces of evil in his own world, and they team up to face a common threat in the Naruto world.
One interesting concept could be a crossover with the Final Fantasy series. You could have characters from Kingdom Hearts interact with iconic Final Fantasy characters in a new world. For example, Sora and Cloud could team up to fight a new threat. Another concept could be a crossover with Disney's Aladdin. Picture Sora and Aladdin going on a new adventure together in the world of the Magic Carpet. A third concept might be a crossover with the Legend of Zelda. Link could join forces with Sora to save both their worlds from a common enemy.
A cool plot for 'the last kingdom fanfic' might be to have a character be transported back in time to a crucial moment in the kingdom's history. They would have the knowledge of what's to come but struggle to convince others to believe them. This could lead to all sorts of interesting twists. Or you could write about a character who is secretly training a group of women to be warriors in a society that doesn't really accept that. It would be about breaking gender norms and the challenges they face in a war - torn world.
Well, a great plot could be Roxas finding himself in a crossover with a Final Fantasy world. He meets some of the iconic Final Fantasy characters like Cloud or Tifa. They initially suspect him because of his connection to the Heartless and Nobodies. But as they get to know him, they realize he's on their side in the fight against a new enemy that is trying to use the power of both the Kingdom Hearts and Final Fantasy universes. It could be a story full of action, character development, and exploring the differences and similarities between the two universes.
One idea could be Aqua crossing over into a different Disney world, like Wonderland. She could have to navigate the strange rules and characters while still maintaining her Keyblade skills. Another could be a crossover with a Square Enix game universe other than Kingdom Hearts. For example, she might end up in the world of Final Fantasy and team up with some of those characters to face a new threat that somehow links both universes.
Well, perhaps in this fanfiction, the Organization XIII has a plan to use Elsa's powers for their own evil purposes. They manipulate events in Arendelle to make Elsa feel isolated and out of control. Sora, Donald, and Goofy show up and befriend Elsa, showing her that she can trust others. They then have to battle the Organization XIII members while also dealing with the internal struggles of Arendelle's characters, like Anna's determination to save her sister no matter what.