Well, the characters from 'Once Upon a Time' are often from fairy tales and have their own set of magic and personalities. The Twilight characters are in a more modern, vampire - werewolf - human love triangle world. If they were to interact, the vampires in Twilight might be intrigued by the dark magic in 'Once Upon a Time'. For example, Edward might be curious about Regina's use of magic and how it differs from his own vampiric abilities. And the werewolves in Twilight could potentially find common ground with some of the more animal - like characters in 'Once Upon a Time'.
The characters would interact in really interesting ways. Consider Belle from 'Once Upon a Time'. She loves books and knowledge. She might be fascinated by the Cullens' existence and their attempts to blend into human society in Twilight. Meanwhile, Jacob from Twilight could get along with some of the more outdoorsy and tough characters from 'Once Upon a Time' like Mulan. They could share stories of their battles and protecting their loved ones. And Bella, being in a world full of fairy - tale like magic in this crossover, would have to adjust to the idea that there are different kinds of 'monsters' and magic than she's used to.
In a crossover fanfiction, the interaction between the characters would be full of surprises. Alice from Twilight, with her ability to see the future, could be a great asset or a source of confusion in the world of 'Once Upon a Time'. Her visions might not always work as expected due to the different rules of magic there. On the 'Once Upon a Time' side, Snow White's kindness and leadership could have an impact on the often - brooding and angsty characters in Twilight. She might try to bring a sense of hope and unity among them. Also, Rumpelstiltskin's deals and magic could create all sorts of chaos or alliances when combined with the Twilight world's power dynamics.
One interesting plot could be that a dark force in 'Once Upon a Time' decides to use the power of the vampires and werewolves in Twilight to take over both worlds. The characters from both universes would have to team up to stop it. The heroes like Emma from 'Once Upon a Time' and Edward from Twilight would lead the charge. They would have to learn about each other's powers and weaknesses quickly to be effective.
In a Frozen - Once Upon a Time crossover, Elsa's cautious and self - isolating personality would be really interesting when combined with the world of Once Upon a Time. She might initially be wary of the new characters, but as she realizes they also face struggles, she could open up. Anna's eagerness to make friends and her loyalty would blend well with characters like Belle, who also values friendship. Kristoff would probably get along with the more down - to - earth characters. His no - nonsense attitude could be refreshing in the often - magical and complex world of Once Upon a Time.
Peter Pan might initially see Belle as a potential addition to his Lost Boys. But Belle has her own ideas and goals. She would resist his attempts to make her part of his group. However, as they spend more time together, they start to see the value in each other. Belle might use her intelligence to help Peter with some problems in Neverland, like a shortage of food or a threat from a new magical creature. Peter would use his flying skills to take Belle to places she needs to go for her own quests. Their characters would interact in a way that challenges each other's beliefs and helps them both grow.
Elsa's reserved and powerful nature would contrast with some of the more outgoing characters in Once Upon a Time. For example, she might initially be a bit intimidated by Regina's boldness, but then they could find common ground in their experiences of being misunderstood. Anna's bubbly and adventurous personality would likely make her fit right in with the more adventurous characters like Hook, and they could go on quests together.
Elsa is more reserved and cautious due to her past experiences of accidentally hurting people with her powers. Emma, on the other hand, is bold and impulsive. Their personalities would create an interesting dynamic. Emma would likely encourage Elsa to be more adventurous and take risks, while Elsa might teach Emma the importance of thinking before acting. For example, when they face a difficult situation, Emma would be quick to jump in, but Elsa would make sure they consider all the possible consequences first.
He would probably try to manipulate them. For example, he might deceive the White Rabbit into leading him to valuable magical items.
The vampires in Twilight are often more reserved and struggle with their inner 'humanity' more than those in True Blood. So, a character like Carlisle from Twilight might try to teach some of the True Blood vampires about self - control. In return, a True Blood vampire like Eric could show Carlisle how to be more assertive in the vampire world.
Hermione would first be very curious. She'd start by observing the different types of magic and how they work in the Once Upon a Time universe. She'd likely try to find similarities to the magic she already knows. For example, she might notice how some curses are similar to dark magic she's studied at Hogwarts.
The Ghost Rider's hellfire ability would be a major factor. Vampires in Twilight are vulnerable to fire, so the hellfire could be a huge threat. Werewolves, on the other hand, are more in tune with nature. They might be able to sense the otherworldly nature of the Ghost Rider and either be in awe or try to fight it. The vampires' super - speed and strength might not be enough against the Ghost Rider's supernatural powers.
In a crossover, the Cullens from Twilight could try to blend in with the Sons of Anarchy community. Carlisle, being a doctor, could offer medical help to the gang members, which would start to build a relationship. However, the gang's illegal activities might put the Cullens in a difficult position. Esme could try to be a mother figure to some of the younger gang members, but the cultural differences between their two groups would make for an interesting dynamic.