Another plotline could involve Percy making new friends in the navy. These friendships could be tested during dangerous missions or when faced with internal conflicts within the naval unit.
It could be a senior officer who has a grudge against Percy for some reason. Maybe Percy accidentally made him look bad in front of the higher - ups early on.
One possible plotline could be Sakura using her medical skills in a new way in the ANBU. For example, she might develop new medical jutsu to heal ANBU members during dangerous missions more effectively.
Another plot could involve Irene using her unique powers to help Fairy Tail in a big crisis. Maybe there's a powerful enemy threatening the guild and her abilities are crucial in the fight. For example, she could use her magic to turn the tide in a battle against a dark guild.
A plotline could involve Tony Stark joining Hydra to spy on them for the Avengers. He pretends to be on their side, but secretly feeds information back to his old team. Along the way, he has to be careful not to get caught and also has to deal with Hydra members who start to suspect him. This would create a lot of suspense and action in the fanfiction. Also, there could be a plot where Tony tries to change Hydra's ideology from within, using his charm and intelligence, but it turns out to be a much harder task than he thought.
One possible plotline could be that Harry, after being abused, feels a sense of desperation and a lack of support from the good side. He might be lured by Voldemort's power and the false promises of a new order where he won't be abused. Voldemort could manipulate Harry by showing him a different way of life, perhaps one where he has more control and respect.
Perhaps Harry joins Voldemort because he believes he can change him from the inside. In this fanfiction, Draco could be the one who initially tries to stop Harry but then realizes that Harry's plan might actually work. They then form an unlikely alliance to bring down Voldemort's more evil plans while Harry is still pretending to be on Voldemort's side.
One possible plotline could be about an old man who is a huge Navy fan. He could be facing some legal issues related to his passionate support for the Navy. Maybe he's protesting against a new law that restricts Navy-related activities in his town. And his fierceness comes out as he tries to fight this law.
A possible plotline could be Percy being assigned to a top - secret mission by Shield. He has to use his unique skills to infiltrate an enemy organization. Another plotline might be that Percy discovers a conspiracy within Shield itself and has to decide who to trust while trying to expose it.
Perhaps Medusa has some crucial information that Percy needs to save the world, and in order to get that information, he has to protect her from other threats. So he embarks on a journey to keep her safe.
One possible plotline could be that Percy has been kidnapped by some mysterious enemy. Maybe it's a new villain who has a vendetta against him. His friends then start a search mission to find him, facing various challenges along the way.