First, understand the core elements of both universes. For bnha, it's the quirks and the hero society, while for kny it's the breathing techniques and the demon slaying corps. Then, find a common ground. Maybe a new type of threat that affects both worlds, like a group of villains who can use both quirks and demon - like powers. This can bring the characters together in a believable way.
You could also base the plot on a character - driven story. For instance, if a character from kny has a family member who has a quirk - like ability in the bnha world. This character travels to the bnha world to find a cure or understand this strange power. Along the way, they meet various bnha characters and form alliances. As the story progresses, they discover that there are deeper connections between the two worlds that they need to explore.
Another way is to check out fanfic communities on Reddit. There are subreddits dedicated to both 'Demon Slayer' and 'My Hero Academia' where people might share or recommend 'kny x bnha' fanfics. You can also post a request for such fanfics there and the community might be able to help.
A great one is 'When Demons Meet Heroes'. This fanfic explores how the characters from 'kny' would fare in the world of 'bnha' and vice versa. It has some really cool fight scenes where the skills and quirks from both sides are pitted against each other. It also delves into how the two different cultures in the shows would interact.
One idea could be to have characters from Boku no Hero Academia (bnha) and Demon Slayer (kny) participate in a joint training session. For example, Deku from bnha could learn some swordsmanship techniques from Tanjiro of kny. This would create an interesting dynamic as they come from different worlds with different power systems.
First, find a common ground between the two universes. For example, both have a system of power (chakra in Naruto and Pokemon types in Pokemon). You can base the plot on how these two power systems interact. Second, consider the characters' personalities. Don't make them act out of character. If Naruto is in the fanfic, he should still be the determined and somewhat goofy hero. Third, introduce a threat that neither world can handle alone. This forces the Pokemon trainers and ninjas to work together.
First, do research on shark behavior. For example, if you write that a shark is acting friendly towards a human, you should base it on real - life examples of sharks showing curiosity rather than aggression. Second, set up a good reason for their interaction. Maybe the human is a marine biologist studying shark migration patterns. Third, add conflict. It could be that the human's research is being threatened by illegal fishing activities that also endanger the sharks.
Perhaps there could be a plot where a villain in the bnha world discovers a way to summon demons from the kny world. This causes chaos as the demons start attacking the cities. The heroes and the Demon Slayer Corps then have to team up. The bnha characters use their quirks to support the kny characters in battles, like Bakugo using his explosions to create distractions while the kny characters go in for the kill.
When creating an OC for a 'bnha x oc fanfic', you need to consider all aspects of their character. Their quirk is just the start. Think about their upbringing. If they were raised in a poor neighborhood, they might have a different perspective on heroism compared to someone from a wealthy family. Their education also matters. Did they go to a regular school before U.A. or were they self - taught? Their values play a big role too. Are they more focused on justice or on protecting the weak? And don't forget about their goals. Are they aiming to be the number one hero, or do they have a more specific goal like finding a cure for a certain quirk - related disease? By carefully considering all these elements, you can create an OC that feels like a natural part of the BNHA world.
You need to consider the world - building aspect. Decide if it's a modern - day encounter or a prehistoric setting. If it's modern - day, how does society react to the presence of a female dinosaur? What laws are in place? And for the characters, give them believable motives. The human might be motivated by a desire for discovery or a sense of adventure, and the female dinosaur could be motivated by self - preservation or a need for companionship.
Develop their relationship gradually. Start with small interactions like sparing each other's lives in battles or having short conversations. Then, as the story progresses, these interactions become more meaningful and frequent. For example, the villain could start leaving little hints or gifts for the hero that show their growing affection. Also, give reasons for their attraction. It could be the hero's sense of justice that the villain secretly admires, or the villain's intelligence that intrigues the hero.
First, you need to define the rules of the mermaid world. For example, how do they breathe underwater? Are there different types of mermaids? Then, describe how the two worlds interact. Maybe there are secret coves where mermaids and humans can meet. Also, add details about the mermaid society like their hierarchy and traditions. This will make the world seem more real.