Well, it could be like Merida joining the Avengers. Maybe she uses her archery skills to help them in a battle. For example, in a fight against some powerful alien invaders, Merida's precise shooting takes out key enemies, impressing the likes of Hawkeye and Black Widow. She could also teach them some wilderness survival skills that are useful during their off - base missions.
In a Brave and Avengers crossover fanfiction, Merida could bring the concept of fate and changing one's own destiny to the Avengers. They've always been about fighting for the greater good, but sometimes they're bound by their own pasts and the events that led them to be heroes. Merida, who defied her own fate in Brave, could inspire them to break free from any self - imposed limitations. Maybe she teams up with Captain America, who also has a strong sense of right and wrong and self - determination. Together, they could lead the Avengers in a new direction, not just fighting against villains, but also fighting against the constraints of their own heroic legacies.
I think Merida and Black Widow would be great together. Black Widow is all about stealth and combat skills in a more urban and high - tech environment. Merida, on the other hand, is used to the forests and castles. Black Widow could teach Merida about modern espionage and Merida could show Black Widow how to use the environment in a more natural, primitive way for combat and survival. They could also bond over being strong - willed women in a world dominated by men.
One idea could be that the Avengers get transported to a Disney fairy - tale world. For example, they end up in Arendelle from 'Frozen'. Iron Man could try to figure out how to adapt his suit to the cold, while Captain America tries to lead the way through the icy terrain. Thor might find similarities between the magic in Arendelle and Asgardian magic.
If Peter Pan joined the Avengers, he would bring a sense of whimsy. He could use his ability to fly and small size to his advantage in battles. For example, he could fly into enemy strongholds unnoticed and gather intelligence.
I think Black Widow and Mulan would make an interesting pairing. Both are strong female characters. They could share their combat skills and stories of survival. Black Widow could learn some of Mulan's more traditional combat techniques, and Mulan could get tips on modern espionage from Black Widow.
Well, in such a crossover, Peter Pan could use his flying ability to outmaneuver the Avengers at first. Maybe he'd steal Captain America's shield just for fun. Then the Avengers would have to figure out how to deal with this mischievous boy who doesn't play by their rules. Iron Man could try to use his technology to track Peter, but Peter's magic might interfere with it.
Once upon a time in the land of Berk, Hiccup was flying on Toothless when a strange magic portal opened. Out of it came Merida from the land of DunBroch. Hiccup was startled but curious. Merida was amazed by the dragons. They decided to team up. Hiccup showed Merida how to ride Toothless and in return, Merida taught Hiccup some of her archery skills. Together they went on an adventure to save both their lands from a common enemy that was using dark magic.
One idea could be that Nightwing is transported to the Avengers' universe through some sort of interdimensional rift. He then has to team up with the Avengers to fight a common enemy, like Thanos who has somehow acquired some of Batman's tech. Nightwing's acrobatic skills and detective abilities would be a great addition to the Avengers' power set.
One idea could be that Godzilla is drawn to the energy source of one of the Avengers' tech, like Stark's Arc Reactor. This causes chaos as Godzilla approaches the city where the Avengers are based. The Avengers initially see Godzilla as a threat and try to fight it. But then they realize that an even bigger alien force is using Godzilla's presence as a distraction. So, they have to find a way to communicate with Godzilla and work together to defeat the common enemy.
First, you need to know both universes well. Study the characters, their abilities, and the settings in Brave Frontier as well as the other franchise you want to cross it with. Then, come up with an interesting premise for the crossover. For example, if it's a crossover with 'Dragon Ball Z', you could have the reason be a rift in the multiverse. Next, plan how the characters will interact. Will they be friends or foes? After that, start writing the story, making sure to keep the tone and style consistent with the original Brave Frontier while also incorporating elements of the other franchise.
A crossover with Moana might be interesting too. Moana could take Elsa and Anna on a journey across the ocean in her boat. Elsa could use her ice powers to create paths or structures on the water. They could face challenges like sea monsters and learn from each other's different ways of life.