A great idea for a Percy Jackson Hollow fanfiction would be to set it during a time when the normal rules of the Hollow are all messed up. Maybe there's a magical glitch that causes time to run differently or makes the creatures act out of character. Percy and his friends would have to figure out what's causing this and how to fix it. They might encounter some strange and dangerous situations along the way that they've never faced before in the Hollow.
One idea could be to explore the hidden parts of the Hollow that the main characters haven't discovered yet. Maybe there are ancient secrets or powerful artifacts there. Another could be to create a new character who is a descendant of a minor god and has a unique connection to the Hollow. They could bring a fresh perspective to the story.
One idea could be a fanfiction where Percy and his friends go on a new quest in a modern, urban setting. Instead of the usual mythological locations, they have to deal with monsters hiding in big cities. Another idea is a story that focuses on the relationships between the characters in a more in - depth way, like exploring the friendship between Percy and Grover during their off - quest times. And a third idea could be a time - travel fanfiction, where Percy gets sent back to the time of the ancient Greek heroes and has to interact with them while still holding onto his modern values.
One idea could be to explore Percy's life after he has fully mastered his powers. Maybe he goes on a quest to find a long - lost relative who also has demigod powers. Another could be a story where Percy and his friends have to deal with a new type of monster that is immune to their usual weapons and they have to find a creative way to defeat it.
One plot idea could be Percy having to team up with Hera to rescue a group of demigods who have been captured by an ancient monster. Hera, despite her usual aloofness, realizes she needs Percy's unique skills.
One idea could be a crossover with the Harry Potter universe. Percy could visit Hogwarts and have to deal with both magical and mythological threats. Maybe he'd team up with Harry to defeat a common enemy that combines dark magic and ancient Greek monsters.
Well, you could write a fanfiction where Percy loses his memory and has to rediscover his powers and his place among the demigods. Or perhaps a story about how the minor gods in the Percy Jackson universe form their own alliance because they feel overlooked by the Olympians. You could also create a fanfic that focuses on Annabeth's journey if she was separated from Percy and had to fend for herself in a dangerous situation.
Another interesting concept is a story where Percy Jackson is somehow transported to the Marvel universe. He could use his water - controlling powers in unique ways there. Maybe he'd join forces with Namor, the Sub - Mariner, and they'd have an underwater adventure together, facing off against some underwater threat that only their combined powers could handle.
Well, one interesting idea could be Percy having new powers or abilities. Maybe he's reborn with the power to control not just water, but also other elements like fire or air. Another could be his relationships being different. For example, his friendship with Grover might start off on a more competitive note instead of being friendly from the start. And also, the whole concept of him being reborn might mean he has a different view of the gods, perhaps more skeptical or more understanding depending on his new experiences.
One idea could be exploring Percy's life if he had a different godly parent. For example, if he was a son of Hades, how would his powers and his relationship with the other demigods change? Another idea is to write about a time - travel adventure for Percy and his friends, where they go back to the era of the first Olympians.
One idea could be to create a fanfiction where Percy has to face a new type of monster that is a combination of different mythological creatures. For example, a centaur with the wings of a griffin and the head of a Medusa. Another idea is to write about Percy's adventures in a modern city that has been magically hidden from the mortal world, full of demigods and mythical beings living in secrecy. Or you could write a fanfiction about Percy training a new group of demigods, passing on his skills and knowledge.
You could also write a fanfiction where the primordial gods start to reawaken in the modern world. Percy has to figure out how to deal with them while also protecting his friends and Camp Half - Blood. The primordial gods' powers and motives are very different from the Olympian gods he is used to, so it would be a huge challenge for him. He might have to learn new magic or tap into his own latent abilities that he didn't even know he had.