One idea could be that Naruto somehow gets infected with the Venom symbiote. He might initially struggle to control it, but then use its power to enhance his ninjutsu. For example, the symbiote could give him an extra boost in speed and strength during battles, like when he's facing tough opponents like Madara. It could also change his appearance, maybe adding some black markings similar to the Venom look, which could be a new form for him in the story.
One common theme is the struggle between loyalty and duty. The Shield Agent often has to balance their loyalty to their agency or organization with their newfound connections in the Naruto world. Another theme is the exploration of hidden powers. Since they are agents, they might have some special abilities that they discover while in the Naruto universe.
One possibility for an 'agent of hell naruto fanfiction' is that the agent is actually a reincarnation of a former Naruto villain who has been reborn as an agent of hell. This character has all their previous knowledge and now enhanced powers from hell. They start by targeting the Leaf Village first, aiming to destroy it from within. They might use mind - control on some of the villagers or create internal disputes among the ninja clans. The story could then be about how the new generation of ninja, led by Naruto, discovers the truth behind this agent and battles to save their village.
The plot might involve Naruto being influenced by some chaotic force. He could then start to question and break the rules that have long governed the ninja villages. For example, he might try to create a new system where power is more evenly distributed among all ninja, regardless of their birth or clan. This would surely cause chaos as the traditional clans and village leaders would oppose such a radical change.
Steve Rogers could be a great ally. Steve's strong sense of justice and leadership would mesh well with Naruto's own values. They both have a history of standing up against powerful enemies. Steve could also learn a lot from Naruto's unique fighting style and his ability to never give up. For example, Naruto's use of chakra to enhance his physical abilities might inspire Steve in new ways of combat.
A crossover could work by having a common enemy. Let's say there is an entity that wants to take over both universes. Naruto and Agent Venom would meet while investigating this threat. They would find that their powers complement each other. Naruto's ability to create multiple clones could be used as a distraction while Agent Venom sneaks up on the enemy. Agent Venom's resistance to physical damage could also protect Naruto in dangerous situations. Their relationship could start off rocky due to differences in their personalities and fighting styles, but they would gradually learn to work together as they face greater challenges.
Often, Naruto and Agent 47 are paired as they are the main characters from their respective universes. Their interactions can be really interesting as they come from such different worlds. Naruto's exuberance and Agent 47's cold, calculated nature create a great contrast.
A more complex plot could be a crossover where an evil organization is trying to take over both universes. Naruto and Agent 47 have to find a way to work together, despite their very different backgrounds and methods. They could learn from each other's strengths and overcome their differences to save both their worlds.
One unique plot idea could be Agent Naruto being sent on a mission to a modern - day world to stop a group of villains who are using ninja techniques for evil in a world not used to such powers. Another might be Agent Naruto having to team up with his own enemies from the Naruto universe, but in a different, more complex political setting within the fanfiction's world.
The Akatsuki could still be the main villains. In a secret agent Naruto fanfic, they could be even more devious, using undercover agents of their own to disrupt the shinobi world while Naruto tries to stop their grand plan of collecting all the tailed beasts.