In this fanfiction, perhaps Percy is magically bound to Artemis as her true guardian. This bond gives him some of her powers and also some of her weaknesses. He then has to learn how to control these new aspects of himself while protecting her from a conspiracy within the Olympian council. Some members of the council believe Artemis is becoming too powerful and they want to find a way to limit her power. Percy has to figure out who is behind this conspiracy and stop them before they can harm Artemis.
Well, a great plot could involve Percy being the only one who can break a curse that has been placed on Artemis. This curse makes her vulnerable in a way she never has been before. Percy then has to go on a quest to find the ingredients for a potion to break the curse. Along the way, he has to fight off various mythological creatures that are trying to stop him because they want Artemis to remain weak. He also has to deal with the fact that some of the gods are against him helping Artemis as they see her as too independent.
One idea could be Percy having to protect Artemis from a new and powerful monster that has a special ability to track her. Another could be Percy and Artemis teaming up to retrieve a lost magical artifact that is important for the balance of the world. Maybe Percy has to enter Artemis's domain in the forest and face challenges there while protecting her.
One idea could be a quest where Percy and Artemis have to team up to rescue a group of demigods captured by a powerful new enemy. Maybe a Titan who has found a way to drain the powers of young demigods. Percy's skills in water manipulation and combat, combined with Artemis's archery and her connection to the moon, would make for an exciting adventure as they face various challenges along the way.
One idea could be Percy having to face a new and powerful enemy that is secretly being controlled by an ancient god who has a grudge against the Olympians. He'd have to use his unique powers and the help of his friends in unexpected ways.
A cool plot could be Percy getting lost in a different dimension that is related to the Greek mythology but has been forgotten. In this dimension, he has to find his way back while also helping the lost souls there. He could learn new powers and make new allies that would be useful when he returns to his own world.
A great plot idea is Percy being chosen by Artemis to be a special liaison between the Hunt and Camp Half - Blood. This would create a lot of interesting interactions as he tries to balance the needs and cultures of both groups. He could also face challenges from within both camps as some might not trust his new role. Also, a plot where Percy discovers a lost relic that is important to the Hunt and has to go on a quest with the Hunters to restore it could be really engaging.
A plot could revolve around Percy being falsely accused of stealing a powerful artifact from the Hunters. He then has to prove his innocence while also protecting the Hunters from those who really stole the artifact and are now using it to target the Hunters. He teams up with some of the more skeptical Hunters who initially thought he was guilty, and together they uncover the real culprits.
Perhaps there's a powerful artifact that can only be activated by a father - daughter bond between Percy and Artemis. They are forced to work together to find and use this artifact to stop a great catastrophe. Along the way, they face many challenges. Percy has to deal with the fact that Artemis is a very different kind of 'daughter' compared to what he might expect, and Artemis has to come to terms with having a father figure for the first time in her existence.
One plot idea could be Fem Percy Jackson joining Artemis' hunt. Since Percy has her own set of skills and powers, it would be interesting to see how she adapts to the life of a hunter. Maybe she could bring a new perspective to the group and help them in ways they haven't thought of before.
One interesting plot idea could be Percy having to team up with Artemis on a quest that involves an ancient artifact that has the power to disrupt the balance between the gods. Maybe it's an artifact that can control the tides in a way that endangers both land and sea. Another idea is a story where Artemis is somehow in danger and Percy has to use his skills and connection to the sea to save her while also dealing with her hunters who are initially suspicious of him. And a third plot could be about Percy and Artemis finding a new, unknown demigod who has powers that are a mix of the sea and the moon, and they have to figure out how to train this demigod and protect them from those who would misuse their powers.
One idea could be that the child has unique powers inherited from both Percy and Artemis. For example, the ability to control water like Percy and also have a strong connection with the moon and hunting like Artemis. Another plot could involve the child trying to find their place in the demigod world, being part of two very different lineages. They might face challenges from both sides, some who are suspicious of their mixed heritage.
Here's a more complex plot. In the fanfiction, Percy discovers that there's a prophecy related to the Hunters of Artemis that could change the balance of power between the gods. He's drawn into this mystery as the Hunters suspect he might be the key to either fulfilling or preventing the prophecy. Along the way, he forms an unexpected bond with one of the hunters, which causes some internal conflict among the group, as they have sworn off relationships with males. This would create a lot of drama and interesting character dynamics.