One idea could be Naruto being transported to the world of Assassin's Creed Syndicate. He could use his ninja skills, like shadow clones, in the context of the Assassin's Creed world. For example, his clones could be used to distract the templars while he sneaks in to steal an important artifact.
Another plot could involve Naruto's nine - tailed fox form. In the Assassin's Creed Syndicate world, the templars might mistake the fox for some sort of ancient, demonic force. The assassins, on the other hand, could see it as a powerful ally. Naruto has to figure out how to control the fox's power in this new world while also helping the assassins fight the templars.
Maybe Naruto teams up with the assassins in Syndicate. He could teach them some of his chakra - based techniques in exchange for learning their stealth and combat skills. They could then go on a joint mission to take down a powerful templar who has some sort of connection to a powerful ninja - like power source.
You could write a fanfic about how the Syndicate interacts with other Assassin's Creed groups around the world. The Frye twins might receive a message from an Assassin cell in another country asking for help. This could involve traveling to a new location, facing new enemies, and learning about different Assassin traditions. It would expand the world of Assassin's Creed Syndicate and show how the fight against the Templars is a global one.
One idea could be that Naruto, with his unique ninja skills, is somehow transported to the world of Assassin's Creed Syndicate. He might mistake the Assassins for a new type of ninja clan. He could then learn their ways of stealth and parkour, while also teaching them some of his jutsu. For example, his shadow clone jutsu could be used to create distractions during assassinations.
An interesting plot could involve an OC who is a foreign Assassin sent to London to assist the Frye twins. This OC could bring in different combat styles and Assassin techniques from their homeland. Maybe they have a special connection to an ancient artifact that the Templars also seek in London. As the story progresses, the OC could form a strong bond with the Frye twins and together they face the Templar threat in a more coordinated and strategic way.
One idea could be that Naruto, with his ninja skills, somehow gets transported into the Assassin's Creed Rogue world. He might mistake the Assassins for some new type of ninja clan. He could then use his unique jutsu, like the Shadow Clone Jutsu, in battles against the Templars. For example, he creates a horde of clones to distract the enemy while he sneaks up on them like an Assassin.
One idea could be that Naruto, with his ninja skills, gets transported to the Assassin's Creed world. He teams up with the Assassins and in the process, attracts a harem of both ninja and Assassin women. They are drawn to his unique abilities and his unwavering determination.
A possible plot could involve an Assassin from Assassin's Creed Origins finding a way into the Naruto world. He discovers the chakra system and tries to incorporate it into his assassin skills. Naruto and his friends become intrigued by this strange visitor and his different fighting style. They team up to stop a group of rogue ninjas who are trying to steal ancient artifacts from both worlds.
A great plot for Assassin's Creed 3 fanfiction could be an alternate ending. For example, what if Connor had managed to convince Haytham to join the Assassins? This would completely change the story's dynamic. Or, a story could be written about Connor's adventures in a different part of the world, like exploring Europe during the same time period. He could encounter new Assassins or Templars there and have to adapt his skills. Also, a fanfiction could center around the impact of Connor's actions on the future of the Assassin Brotherhood in America.
One idea could be that Naruto, with his ninja skills, gets transported to the Assassin's Creed world. He might mistake the Assassins for a new type of ninja. He could then start learning their ways, like using the hidden blade in combination with his own jutsu. Another plot could involve Naruto teaming up with an Assassin to take down a powerful enemy that is causing chaos in both the Naruto universe and the Assassin's Creed universe.
A really interesting plot would be if the Akatsuki from Naruto were somehow related to the Templars in Assassin's Creed. Maybe they share a common goal, or there's a power struggle between them. Or, imagine a scenario where Sasuke becomes an assassin. He already has the skills and the brooding personality. He could use his Sharingan to enhance his assassin abilities, like predicting enemy moves better.
Overall, the story of Assassin's Creed Syndicate is impressive. It has a rich historical backdrop and interesting character developments. The plot keeps you hooked throughout the game.