Well, you could write a fanfic where a new type of kaiju is introduced into Kaiju Paradise. This kaiju has unique abilities that no one has seen before. The main character is a scientist or a researcher in the park who tries to study this new kaiju. Along the way, they face challenges from the park's management who don't want the public to know about this new discovery, and also from the kaiju itself which is very unpredictable.
To create engaging characters for Kaiju Paradise fanfic, think about their motives. Are they in the park because they are thrill - seekers or because they were forced to be there? Also, consider their relationships. A character could have a strained relationship with another character who blames them for a kaiju - related incident. And don't forget about their appearance. A character with a unique look, like a scar from a kaiju encounter, can be very memorable.
Kaiju novels often portray kaiju as gigantic and powerful beings. They are usually depicted as forces of nature that are difficult to control or defeat. For example, in 'Godzilla' novels, Godzilla is shown as a nearly indestructible creature with its atomic breath and massive size.
One popular 'kaiju x kaiju fanfic' story could be about Godzilla and Mothra forming an alliance in a unique way. Maybe they team up against a new, more powerful enemy that threatens their world.
How about a Kaiju that can split into multiple smaller versions of itself? This would be a strategic advantage as the Jaegers would then have to deal with several threats at once. Each smaller Kaiju could have a different ability, such as one being able to spit acid and another being extremely fast.
To write a compelling Kaiju character, start by giving it a distinct appearance. Describe its size, color, and any unique features like spikes or tentacles. For example, a Kaiju with a massive, spiked shell on its back is immediately more interesting.