Well, you could write a fanfiction where the magic in the Wolfblood world somehow interacts with the Greek mythology in Percy Jackson. For example, the moon phases that are important for wolfbloods could have a different effect on the demigods. Maybe during a full moon, the demigods' powers are enhanced in a new and unexpected way. Or perhaps a wolfblood gets sent to Camp Half - Blood by mistake and has to learn to live among the demigods while hiding their true nature.
First, you should familiarize yourself with both universes. Read the Percy Jackson books and watch the Wolfblood series. Then, think of a central concept or plot that combines elements from both. It could be as simple as a character from one world ending up in the other. Start with an interesting hook, like a mysterious event that draws the two worlds together.
One idea could be a wolfblood having to hide their identity in a new school where there are rumors of a werewolf hunter in town. They have to constantly be on guard while also trying to make friends and fit in.
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 idea could be an OC who is a new Wolfblood in a pack and has to prove themselves. Maybe they have a unique power that the others don't have and they have to learn how to control it while fitting into the pack's hierarchy.
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.