In a 'Naruto Monsters vs Aliens' fanfic, perhaps the aliens are trying to enslave the people of the Naruto world. The monsters, which were once feared by the villagers, now become unexpected allies. Naruto, with his belief in friendship and understanding, tries to bridge the gap between the two groups. He might train with the monsters to learn new combat techniques and in turn, teach them about the importance of unity. Together, they could fight against the aliens' mind - control devices and save the world.
In addition to the regular Naruto characters, some of the more powerful monsters could be main characters too. For instance, a giant dragon - like monster that has the power of flight and can breathe ice. It could be a reluctant ally at first but then grow to respect Naruto and his friends. And among the aliens, there could be a leader - type character who is extremely intelligent and has unique powers that pose a great threat to the Naruto world.
The plot involves a group of monsters coming together to fight against aliens. Susan becomes Ginormica and teams up with the likes of B.O.B, Dr. Cockroach, and The Missing Link to save the world from the alien threat.
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.
One plot idea could be that aliens invade the Naruto world seeking a powerful energy source, which is actually the chakra. The Naruto monsters then team up to defend their world. Another could be a group of Naruto monsters getting accidentally transported to an alien planet and having to fight their way back home. They could learn new techniques from the aliens they encounter during their journey.
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.
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.
One idea could be a story where the monsters and aliens have to team up against an even greater threat from another dimension. Maybe a powerful interdimensional being that wants to conquer both Earth and the alien planets.
Naruto's ability to sense danger and his strong willpower could also play important roles. In the Monsters vs Aliens world, there are often unexpected threats. Naruto's danger - sensing ability would help the team anticipate attacks. And his willpower could inspire the monsters when they are facing difficult situations. His ninjutsu skills in general could be combined with the unique features of the monsters, like using the Invisibility of the Invisible Girl and adding his own hidden mist jutsu to create an even more effective stealth attack.
In Naruto Monsters vs Aliens fanfiction, it's hard to say who would win. Naruto's monsters have unique ninja abilities like chakra control and powerful jutsus. However, aliens might have advanced technology and strange powers. If the aliens' technology can disrupt chakra, they could have an advantage. But Naruto monsters are used to fighting in their own world's crazy battles.
The Missing Link is also quite popular. His brash and confident personality can add a lot of humor and action to a fanfic. He could be on a quest for glory or trying to prove himself to the other monsters.