One common element is the power dynamics. Since 'k project' has characters with unique powers, when crossed over with another universe, exploring how those powers interact is often a focus. For example, if crossed with a superhero universe, comparing the powers of the 'k project' characters to those of the superheroes.
Character relationships also play a big role. Writers like to explore how the relationships between characters in 'k project' change when they are in a different setting or interacting with new characters. It could be a friendship or a rivalry. For instance, if crossed with a high school anime, how the hierarchical relationships in 'k project' clans translate to the high school social structure.
One common theme is power struggles. Since K has a complex power structure with Kings and Clans, when crossed over with other series, there are often new power dynamics to explore. For instance, if crossed with a superhero series, how would the Kings' powers compare to superhero abilities? Another theme is identity. Characters from different universes have to figure out their place in this new crossover world. In a K x Naruto crossover, a character from K might struggle with the very different ninja culture in Naruto while still holding onto their own identity from K. And friendship or rivalry is also common. Characters from different series meet and form new relationships, be it friendly like Izaya from Durarara!! making an unlikely friendship with a character from K or rivalrous, like two powerful characters from different universes vying for dominance.
One common theme is the clash of different power systems. Since Naruto has its own chakra - based powers and K Project has its own unique abilities, seeing how they interact and compare is often explored. For example, how would Naruto's Rasengan fare against a K Project character's power?
One common theme is fixing past mistakes. Since the characters can travel back in time, they often try to correct things that went wrong in the original K Project story. Another theme is exploring character backstories more deeply. Time travel allows for a closer look at what made the characters who they are.
Power and its control is a common theme. The male oc often has to learn how to handle new - found powers in the complex world of K project. Another is friendship, as they form bonds with the existing characters in the story.
Love and relationships are also very common. The reader often forms a romantic bond with one of the characters from the K Project, whether it's a king or a member of a clan. It adds a personal touch to the story and makes it more engaging.
A great plot could be centered around a common enemy. There could be a new, powerful force that is a threat to both worlds. So, Naruto and the leaders from the different Clans in K Project have to work together. This would lead to interesting interactions, like Yata from K trying to learn ninja techniques from Sasuke. And also, the political systems of both worlds would clash, making for a complex and engaging story.
You can also try searching on Tumblr. Sometimes fans post their own short 'k project crossover fanfiction' there. Crossovers with a post - apocalyptic setting could be really cool. Picture the clans from 'k project' trying to survive in a world after a major disaster, having to use their powers in different ways to adapt.
One common theme is the exploration of their power struggle. Given their different positions and abilities in the 'k project' world, many fanfictions delve into how they deal with power differences between them.
One common theme is loyalty. Yata is extremely loyal to Mikoto, and this loyalty is often explored in different situations in fanfictions. Another theme is power dynamics, considering Mikoto's strong powers compared to Yata.
One common theme is friendship. Despite the complications, the underlying friendship between them is often explored. Another is redemption. Saruhiko's actions in leaving HOMRA may be seen as something he needs to atone for. And then there's the theme of loyalty, as both have their own loyalties that they struggle with.