You can start by creating a scenario where the two worlds collide. Maybe it's a portal that opens up between the 'Seraph of the End' world and the other world. Then, introduce the main characters from both sides. Show how they react to the new and strange elements in each other's worlds. You could start with a character from 'Seraph of the End' stumbling into the other world by accident.
First, decide which other universe you want to crossover with. This will help you set the tone and the rules of the new combined world. Then, think about how the characters from 'owari no seraph' will interact with the new characters. For example, if it's a crossover with 'Sword Art Online', how would Yuichiro react to being in a virtual world? Next, plan out a basic plot. It could start with a strange event that pulls the characters into the new world.
First, you should re - watch or re - read the series to really understand the characters and the world. Then, pick a concept or idea that interests you, like I mentioned before. After that, just start writing. Don't worry too much about grammar or making it perfect at first.
Begin by establishing the setting clearly. If it's a Joker crossover with a horror universe, describe how Gotham starts to take on elements of that horror world. Then, introduce the Joker in a way that makes sense in this new context. Maybe he's intrigued by the new horrors or sees an opportunity to create more chaos. You also need to consider the characterizations and how they will interact. The Joker's maniacal nature might clash or blend in unexpected ways with the other characters.
First, decide which universe or character you want to crossover with Morbius. For example, if it's Iron Man, think about how their worlds collide. Maybe Morbius' condition attracts the attention of Stark Industries. Then, create an interesting opening scene. It could be Morbius in a situation that leads him to cross paths with Iron Man, like a strange energy signature that both are investigating.
Begin by choosing the right crossover. Let's say it's Negan and 'Harry Potter'. Think about the rules of the 'Harry Potter' world and how Negan would break or bend them. You can start with Negan somehow getting a letter from Hogwarts (maybe a mistake by the owl post). He shows up at the school, and chaos ensues. Write from his perspective as he encounters magic for the first time. His confusion and his attempt to assert his dominance in this new and strange place would make for an interesting start.
Well, start by creating a scenario that brings the Jashin concept into the other story. For example, if it's a crossover with a game world, think about how Jashin's influence could disrupt the game's balance or create new quests. You could also think about the reactions of the original characters to the Jashin - related elements. Maybe they're horrified, or maybe some are intrigued. Then build your plot around these interactions and reactions.
First, choose the two universes you want to cross over. For example, if it's Miraculous and Naruto. Then, think about how the characters will interact. Maybe Ladybug could learn some ninja skills from Naruto. Start with a simple scenario like an akuma attack in a world where ninjas exist.
First, decide which universe you want to cross Chappie over with. For example, if it's "Terminator", research the lore of that universe. Then, think of a plot hook. Maybe Chappie is mistaken for a Skynet creation in the Terminator world. Next, start writing an introduction that sets up the crossover situation.
First, decide which universe you want to crossover with. Then, think about how the Mandalorian's character traits will interact with the new universe's elements. For example, if it's a crossover with Star Trek, consider how his no - nonsense attitude will mesh with the more diplomatic Starfleet officers.
First, decide which two universes you want to cross over. Then, research both of them thoroughly. Know the rules, the characters, and the settings.