One idea could be to combine the powers of the characters from 'Boku no Hero' with the epic battles and mythology of 'God of War'. For example, Deku could find a magical weapon from the 'God of War' universe that enhances his One For All power. Another idea is to have Kratos end up in the 'Boku no Hero' world and his combat skills and Spartan rage could make him a formidable hero or a feared villain. Or perhaps the Titans from 'God of War' could invade the world of 'Boku no Hero' and the heroes have to figure out how to stop them using their quirks.
A possible idea for a 'boku no hero god of war fanfic' is to have a crossover where the training methods in 'God of War' are introduced to the students at U.A. High. Kratos could be a mysterious guest instructor who teaches them about physical and mental discipline in a much harsher way than they are used to. This could lead to some of the students like Bakugo being both challenged and inspired, while others like Mineta might be completely terrified. Also, the artifacts and magic from 'God of War' could be integrated into the story, like a character finding the Blades of Chaos and having to learn how to control them while still using their quirk.
You could also write a fanfic about a time - travel plot. A character goes back in time to prevent a major disaster that happened in the 'boku no hero' world. They have to figure out how to change the past without completely disrupting the future, and along the way, they interact with younger versions of the beloved characters.
One idea could be exploring Stain's backstory in more detail. Maybe his early life experiences that led him to his extreme views. Another could be a 'what if' scenario where Stain teams up with a hero, albeit reluctantly, to take on a greater evil. And a third idea could be to write from the perspective of someone inspired by Stain's ideology but trying to find a more peaceful way to bring about change in the hero society.
Often in 'boku no hero academia god fanfic', there can be a focus on the moral implications of having god - like powers. How would the characters, who are used to a certain set of rules in their world, react when faced with such extreme power? Would they be corrupted by it, or use it for the greater good? This exploration of character development in the face of such power is really fascinating.
A cool plot could be that a villain in the Boku no hero world steals Iron Man's technology and starts creating chaos. The heroes then have to figure out how to stop the villain while also dealing with the unfamiliar technology. Or perhaps a young inventor in the Boku no hero world idolizes Iron Man and tries to recreate his suits, but with a twist related to quirks. This could lead to a story about the young inventor's journey, from being an unknown to becoming a key figure in fighting crime with their unique Iron Man - inspired creations.
One popular idea could be creating an alternate origin story for a character. For example, giving Deku a different quirk acquisition experience that still leads to his growth as a hero.
One idea could be a fusion between Deku and All Might. Imagine Deku having not just One For All, but also All Might's combat experience and charisma from the start. It would change the dynamic of his battles and his relationships with other characters. Another idea is fusing Todoroki with a water - based hero, which could enhance his ice and water abilities even more and lead to new and creative ways of using his quirk in combat and rescue situations.
One idea could be to have the heroes and villains participate in a Halloween-themed battle royale. The setting could be a spooky, abandoned city filled with Halloween decorations. Another idea is to have a Halloween party at UA High School where students dress up as different heroes or villains from history. They could then have a contest for the best costume.
An interesting concept for a 'boku no hero academia oc fanfic' is an OC who is a villain at first but then slowly realizes the error of their ways. Their quirk could be something that is initially seen as very menacing, like the power to steal the quirks of others temporarily. As the story progresses, they could start using this quirk for good, like helping heroes regain their lost quirks in battles against stronger villains.
One idea could be creating a fanfic where a new student with a unique quirk joins U.A. High School. This new character could have a quirk that is both a blessing and a curse, like the ability to control time but at the cost of their own health. Another idea is to write a story about the villains' backstories in more detail. Maybe explore how they became villains and what events led them to oppose the heroes.
A fanfic about Toga falling in love with a civilian. Since she has such an unusual view of the world, it would be fascinating to see how she handles normal relationship emotions. She would have to hide her true nature from the person she loves, and there could be a lot of drama as she tries to balance her two lives - her life as a villain and her newfound love life.