Character development is key. If you're bringing in characters from different franchises, make sure they stay true to their original selves while also growing in the new environment. For instance, if Captain Kirk enters the 40k universe, he would be shocked by the brutality but also use his wits to survive. You also need to think about how the different powers and abilities will interact. In a crossover with Harry Potter, how would a Space Marine react to magic? There are so many possibilities to explore.
One great 'Warhammer 40000 Crossover Fanfiction' is the one where it crosses with Star Wars. It's really interesting to see the Imperial Guard facing off against Stormtroopers. The different combat styles and ideologies make for a great read.
The use of miscommunication is great too. Imagine a group of Imperial Guardsmen trying to communicate with an alien race that has a completely different language and cultural understanding. The guardsmen's attempts to be diplomatic while the aliens are completely misinterpreting everything can lead to some truly laugh - out - loud moments. Also, the cultural differences can be exaggerated for comedic effect, such as the aliens thinking the guardsmen's helmets are part of their mating rituals or something equally absurd.
One idea could be a crossover between Warhammer and Lord of the Rings. Imagine the Space Marines facing off against the Orcs of Mordor. Another could be a Warhammer and Star Wars crossover, like the Imperium of Man encountering the Galactic Empire. Or perhaps a crossover with the Witcher, where Witchers team up with Warhammer's warriors to fight common foes.
A major theme is the exploration of morality. In 'Worm', the concept of 'parahumans' and their actions can be morally ambiguous. In Warhammer, there are also complex moral situations. When the two universes cross over, these moral concepts collide. Authors often use this to explore how characters from different backgrounds with different moral compasses interact and make decisions in new and difficult situations. This can lead to some really thought - provoking storylines that go beyond just the action and adventure aspects of the crossover.
One great aspect of 'Naruto Total War Warhammer Fanfiction' could be the unique character combinations. Imagine Naruto characters in the Warhammer universe, like Naruto using his Rasengan in the midst of a Warhammer battle. It would be a spectacle of different powers and fighting styles colliding.
One interesting concept could be a 'Warhammer' crossover with 'Lord of the Rings'. Imagine the orcs from 'Warhammer' interacting with the orcs from Middle - earth. Another could be a crossover with 'Star Wars', like the Space Marines teaming up with the Jedi or Sith in some strange alternate universe scenario. And a 'Warhammer' and 'Harry Potter' crossover where the magic of the wizarding world meets the dark and gritty world of 'Warhammer' would also be really cool.
First, choose the two universes you want to cross over. For example, if it's Warhammer 40k and Star Trek. Then, research both universes thoroughly. Know the lore, the characters, the technology, etc. After that, come up with a basic plot. Maybe the Starfleet encounters the Imperium of Man and there's a misunderstanding that leads to conflict at first.
Yes, there are quite a few out there. You can start by looking on fanfiction platforms like Archive of Our Own. Some of these crossovers blend the magic system of Harry Potter with the dark and gritty universe of Warhammer in really interesting ways, like having Hogwarts students interact with Warhammer characters.
One great 'Warhammer 40k Emperor Crossover Fanfiction' is the one where the Emperor crosses over into a modern Earth setting. It shows how his powerful psychic abilities and leadership skills shock the modern world.