One interesting concept could be a Godzilla crossover with other giant monster franchises like King Kong. It could lead to epic battles and new storylines where they have to team up or fight over territory. Another concept might be a crossover with a superhero universe. Imagine Godzilla facing off against the Avengers or Justice League, which would require different strategies from both sides.
In crossover Godzilla fanfiction, a cool concept is when Godzilla crosses over with a science - fiction alien race. Imagine Godzilla having to deal with an advanced alien civilization that wants to either study or destroy him. It could create a story full of high - tech battles and negotiations. Additionally, a crossover with a medieval fantasy world could be fascinating. Godzilla in a world of knights and magic, perhaps being seen as a terrifying dragon - like creature that the kingdoms must either appease or find a way to defeat.
One interesting concept could be a crossover with other kaiju from different universes. For example, Shin Godzilla meeting Gamera. It would be a clash of two very different kaiju with their own unique abilities and characteristics.
One interesting concept could be alternate timelines where Godzilla has different powers or allies. For example, in some fanfics, Godzilla might team up with other kaiju to fight a greater threat.
Well, in 'godzilla x evangelion fanfic', a cool concept might be the adaptation of Godzilla's regenerative abilities in the context of Evangelion. Imagine if an Evangelion unit could somehow gain that power. Also, the idea of the Nerv organization trying to study Godzilla's biology and use it to enhance their own mecha or combat strategies is quite fascinating.
One idea could be that Godzilla arrives in the RWBY world due to a strange dimensional rift. The Huntsmen and Huntresses initially see it as a huge threat and try to fight it. But then they discover that Godzilla is actually there to fight a common enemy, like a new type of Grimm that is immune to normal attacks but vulnerable to Godzilla's atomic breath.
Well, for a Shin Godzilla crossover fanfic, it could cross over with the Godzilla: Planet of the Monsters universe. Maybe the events in that universe lead to the emergence of Shin Godzilla in a different way. Or it could cross with the Power Rangers universe. The Rangers could use their powers and zords to fight Shin Godzilla, which would be a really cool scenario with lots of action and drama.
Another concept is the Joker's influence on the story's tone. In a crossover with a more light - hearted or comical universe, the Joker could still bring his dark and menacing presence, which would create a really interesting contrast. His actions and words could disrupt the normalcy of that universe and force the other characters to deal with a level of chaos they're not used to.
Another concept could be a time - travel - based crossover. Suppose Doraemon crosses over with Doctor Who. They could both explore different time periods and dimensions together. Doraemon's Time Machine and Doctor Who's TARDIS are both means of time travel, but they have different functions and appearances. Their combined adventures would be full of mystery and discovery.
One interesting concept is character interactions. For example, seeing how characters from different timelines or universes react when they meet. Another is the alteration of established storylines. It can create unique plot twists.
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.