The relationship might start with curiosity. The OC could be curious about Susan's abilities and Susan could be interested in the OC's origin. As they start to communicate and work together on small tasks, like helping the monsters train for a potential threat, their relationship gradually deepens.
Perhaps the OC is initially distrusted by Susan and the other characters. But as the story progresses, through various adventures and challenges, like facing a powerful alien invader, the OC proves their worth and they form a strong bond with Susan. They might have to combine their unique skills, Susan's size - changing ability and the OC's special weapon or power, to defeat the enemy.
In a fanfiction, the aliens could capture Naruto and try to study his unique abilities. The monsters then decide to rescue him because they realize his powers could be the key to defeating the aliens once and for all. The story could involve a lot of action as the monsters infiltrate the alien base to save Naruto.
In the Monsters vs Aliens original story, a young woman is transformed into a giantess after being hit by a meteor on her wedding day. She is then taken to a secret government facility where she meets other monsters like a half - ape, half - fish creature, a gelatinous mass, and an insect - like monster. When aliens attack the Earth, these misfit monsters are the world's only hope. They use their strange powers and abilities to combat the technologically advanced aliens and ultimately protect the planet.
In a 'Girl vs Monster' fanfic, the girl could be from a long line of monster hunters. She is the only one left in her family though. The monster she's up against is the one that killed her family. This adds an emotional depth to the story as she not only fights for survival but also for revenge. She might use her family's secret techniques to take on the monster.
The main characters often include some prominent Alien queens and Predator leaders. The Alien queens play a crucial role in leading their hordes, while the Predator leaders direct their hunting parties. Their decisions and actions greatly influence the course of the war in the novel.
Power and its consequences is also a theme. The OC may have some special power, and the fanfiction explores what they do with it. They could use it for good, like helping the monsters protect the Earth, or it could lead them astray if they misuse it. This theme adds depth to the story and the character of the OC.
The main characters are probably the dinosaurs and the aliens. For the dinosaurs, it could be well - known ones like T - Rex, Stegosaurus etc. And for the aliens, they could be some strange - looking creatures with unique powers.