Well, for a Naruto Assassin's Creed crossover fanfiction, it might start with Naruto being somehow transported to the Assassin's Creed universe. He'd have to learn the ways of the assassins quickly. His chakra could be seen as a kind of 'hidden power' in that world. And perhaps he'd team up with some of the assassins to take on a common enemy. For example, an evil organization that is threatening both the ninja world and the Assassin's Creed world in some way.
The plot could involve Naruto characters in the Assassin's Creed world. Maybe Naruto himself could be an assassin with his ninja skills. He'd be sneaking around ancient cities, using his shadow clones to distract guards just like assassins use decoys. It would be really cool to see him climb buildings and assassinate targets in a more historical and different setting than the ninja villages.
A possible plot for this crossover could be that the Creed's Apple of Eden has some connection to the tailed beasts in Naruto. Some bad guys are trying to use both the power of the Apple and the tailed beasts for their own evil purposes. So, Naruto and Ezio (from Assassin's Creed) have to work together. Naruto brings his unique abilities like Rasengan and Sage Mode, while Ezio offers his skills in stealth, combat, and parkour. They'd travel between the two worlds, recruiting help from their respective allies, like Naruto's friends from Konoha and Ezio's fellow assassins.
Well, it could have Naruto characters using Assassin's Creed skills like parkour. For example, Naruto could be running across the rooftops of Konoha in the same fluid way as an Assassin. Maybe Sasuke would be like an assassin with his stealth and quick strikes.
One possible plot could be that Naruto, with his ninja skills, gets transported to the Assassin Creed world. He might team up with an Assassin, perhaps Ezio. Together, they could use Naruto's chakra - based attacks and the Assassin's stealth and combat skills to take on a common enemy, like a powerful Templar - like figure who is threatening both the ninja world and the Assassin's world.
A cool plot could be that the Templars in the Assassin's Creed world somehow get hold of some ninjutsu scrolls. They start using these to create an army of super - soldiers. The Naruto characters then team up with the assassins to stop the Templars. Naruto could use his Rasengan against the Templars' new warriors, while Altair could use his eagle vision to spot their weaknesses. Together, they could form a unique combat strategy that combines the best of both worlds.
Imagine if there was a tournament that brought the best fighters from both universes together. Naruto, Sasuke, and the others from the Naruto world, and Kai, Jay, and the rest from Ninjago. They start off competing against each other but then realize there is a greater threat lurking. A group of shadowy figures wants to steal the powers of both ninjas and warriors. So, they must put aside their differences and combine their skills to fight this new enemy.
The plot could involve a threat that requires the combined efforts of both universes. Maybe an ancient evil that can only be defeated by the unique powers of Naruto characters and the technology and superpowers of Marvel heroes. For instance, a villain who can absorb all forms of energy is threatening both the ninja world and the Marvel universe. Naruto and his friends team up with the Avengers to stop this threat. Along the way, they have to learn to work together, which could lead to some interesting character interactions, like Naruto trying to understand Stark's high - tech gadgets or Thor explaining his Asgardian magic to the ninja.
The plot could involve a common enemy that both Naruto and Beelzebub have to face. For example, a powerful demon that threatens both the ninja world and the world of Beelzebub. Naruto's determination and Beelzebub's unique abilities would combine to take on this threat. They might start off as rivals, not trusting each other at first, but as they face challenges together, they form an alliance. Naruto could show Beelzebub the value of friendship and loyalty, which are important themes in his own world.
The plot could involve Naruto characters in a Disney - like world. For example, Naruto might find himself in the world of 'Frozen' and team up with Elsa to stop an evil jutsu - using snow monster. He could use his Rasengan against the icy threats while Elsa uses her ice powers to assist him. This would be a cool mix of the ninja - like action from Naruto and the magical, fairy - tale setting of Disney.
It could be amazing. Picture assassins in the world of Westeros. They might use their skills to navigate the political intrigue. Maybe they'd target the corrupt lords or help a rightful heir claim the throne. Their stealth abilities would give them an edge in the cutthroat world of Game of Thrones.
I think Naruto would be the most interesting. His energetic and determined personality would make for great stories in the Assassin's Creed world. He'd be constantly trying to adapt and use his ninja skills in new ways. His ability to make friends and inspire others would also lead to some interesting interactions with the assassins.
I think Sasuke would be quite interesting. His dark past and thirst for power could be paralleled with some of the Assassin's Creed characters' motives. He could learn new ways to use his skills in the Assassin's Creed world and maybe even find a new purpose.