One idea could be that Naruto is transported to the world of Lollipop Chainsaw. He might use his ninja skills to fight the zombies there. His shadow clone jutsu could be really useful in confusing the zombies and helping Juliet Starling, the main character of Lollipop Chainsaw.
Another idea is a story where a character from the Chainsaw Man universe ends up in the Naruto world. This could lead to all sorts of chaos as they introduce their unique abilities and concepts. For example, they might try to teach Naruto and his friends about devil contracts in the context of the Naruto world's power system.
First, come up with a basic plot. Decide if it's a crossover or just a new take on the Naruto world with chainsaw elements. For example, if it's a crossover, figure out how the two universes will interact.
A fanfic could revolve around a tournament. Characters from Naruto and Lollipop Chainsaw are forced to participate in a deadly tournament. Naruto and Juliet form an alliance early on. They face off against various opponents, some with unique jutsu - like abilities from Naruto's world and some with the grotesque powers of the zombies from Juliet's world. Along the way, they also learn about each other's cultures and values.
Naruto himself would be very friendly and eager to help. He would probably be fascinated by Juliet's chainsaw and ask a lot of questions about it. He might even try to use it himself in a comical way at first. His positive attitude would likely boost the morale of the Lollipop Chainsaw characters.
In a fanfic, the Chainsaw concept can be integrated with Naruto by creating a new type of jutsu that is based on chainsaw mechanics. For instance, a character could create a chakra - powered chainsaw that can cut through any substance. This would change the dynamics of battles in the Naruto universe, as opponents would need to find new ways to defend against such a powerful weapon. Also, the chainsaw could be used as a tool for things like building or exploring in the Naruto world, adding a new dimension to the story.
One idea could be a crossover where Naruto characters get their hands on chainsaws in a strange, alternate universe. Maybe Naruto uses a chainsaw - like weapon as an extreme version of his Rasengan, spinning it around for a super - powerful attack.
Sasuke from Naruto might be a bit skeptical of Juliet at first. He could see her as a distraction. But as they face a common enemy, like a powerful zombie horde, he starts to respect her skills. And Juliet might be intrigued by Sasuke's dark and brooding nature. There could be a lot of tension and cooperation between them.
Fanfiction about Makima can also explore her powers in new ways. Her ability to control others is a key part of her character. A writer could create a story where Makima's powers backfire on her, leading to unexpected consequences.
Chainsaw Man x Male Reader fanfiction often explores unique relationships. It can show the male reader character interacting with the Chainsaw Man universe in various ways. For example, the reader might be a devil hunter alongside the main characters. This allows for different plot developments, like facing powerful devils together and building friendships or rivalries within the story.