In some 'naruto is king fanfiction', a great plotline is when Naruto uses his new - found 'kingship' to reform the shinobi education system. He could introduce new training methods that focus not only on combat but also on emotional intelligence and diplomacy, making the next generation of ninjas more well - rounded.
One interesting plotline could be the Chaos King's impact on the power balance in the Naruto universe. Maybe he brings a new kind of jutsu or power that challenges the existing ninja clans. Another could be his interactions with Naruto himself, like how Naruto tries to either convert him to a more positive path or has to fight against his extreme chaos - inducing ideas.
One interesting plotline could be Edward's rule over the vampire kingdom. He might face challenges from other powerful vampires who don't want to accept his authority. Another could be his relationship with a human in this new role as king. Maybe he tries to protect her from the more dangerous aspects of the vampire world while still maintaining his position.
One possible interesting plotline could be the power struggles within the twilight world that the king maker character might influence. For example, the fight for territory among different vampire clans.
One possible plotline could be Harry using his new position to reform Slytherin house. He might change the way Slytherins are perceived in Hogwarts, promoting unity among all the houses.
Perhaps Naruto discovers a new medical jutsu that combines his chakra control with traditional medical knowledge. This could revolutionize the medical field in the Naruto universe. He might use it to heal previously incurable diseases or injuries, and in the process, gain the respect of the medical community. This could also lead to some interesting interactions with other medical ninja, like Shizune or Tsunade.
Well, in some fanfics, there's a plotline where Hinata loses her memory and Naruto has to make her fall in love with him all over again. It's a classic but still very engaging. There are also stories where they are arranged to be married for political reasons at first, but then they actually fall in love for real during the process. And a really unique one is when Hinata becomes a super powerful ninja overnight and Naruto has to deal with his feelings of being a bit overshadowed while also being proud of her.
One interesting plotline could be Naruto joining the Akatsuki and trying to change it from the inside. He might use his ideals of friendship and peace to influence the other members who have mostly known a life of darkness and violence.
One interesting plotline could be Shizune's involvement in secret medical research within the Hidden Leaf. Maybe she discovers a new form of medical ninjutsu that could change the way they treat serious injuries. Another could be her relationship with Naruto from a medical - training perspective. She helps him understand the importance of medical skills for a ninja, and they bond over that.
One plotline could be Scathach training Naruto in some ancient and powerful techniques that are not known in the ninja world. This would give Naruto an edge over his enemies and also lead to interesting interactions between them as Naruto tries to master these new skills.
One interesting plotline could be Naruto dealing with the complex political landscape of the Hidden Leaf as an adult. He might have to make tough decisions regarding alliances and the future of the village.