How about a Thor fanfic where he gets stuck in the modern world without his powers? He has to learn to adapt and survive like an ordinary human, which would be a great opportunity to show his character growth and his ability to overcome challenges without relying on his godly abilities.
The unique element is the combination of two very different power systems. Thor has his godly powers like lightning and super strength, while Naruto has chakra - based abilities like shadow clones and rasengan. When these two meet in a fanfic, it creates exciting new combat scenarios.
The unique element is the blend of different mythologies. Thor comes from Norse mythology and Harry from the wizarding world which has its own kind of magic lore. Their combination creates a whole new set of possibilities in terms of powers and adventures.
One idea could be Thor trying to keep the peace between two warring factions within Asgard during the Civil War. He might use his strength and wisdom to negotiate treaties.
One idea could be a story where a character discovers they have a special power related to bladder control. For example, they can hold their bladder for an inhumanly long time and this becomes a crucial part of a mission they are on, like infiltrating a place where there are no restrooms available. Another could be a more comical approach where a group of friends have a bladder control contest and the chaos that ensues from that.
One idea could be to set the story in a modern - day city. Cupid could be a famous love blogger, and Psyche could be a skeptic who doesn't believe in true love. They meet at a coffee shop, and Cupid tries to convince Psyche of the power of love through his stories. Another idea is to have Psyche be a scientist who is researching the chemical basis of love, and Cupid is the inspiration for her research, appearing to her in visions and leading her to new discoveries.
One idea could be a time - travel fanfic where Naruto and Koneko are sent back in time. They have to adapt to the different ways of the past while also trying to find a way back to their own time. This would give them the chance to meet younger versions of their friends and family, and perhaps change the course of history in small but significant ways.
One plot involves Thor losing his memory but still having his powers. The Avengers have to help him regain his memories while also dealing with a new enemy that is targeting Thor because of his weakened state. This creates a lot of emotional and action - packed moments as the team tries to protect him and restore his identity.
One idea could be that the Avengers find themselves magically transported to the wizarding world. Thor, with his Asgardian magic, might have an interesting interaction with the Hogwarts professors. Maybe they team up to fight a new, combined threat that is both magical and technological.
One idea could be Loki, in his Jotun form, is initially feared by Thor but then Thor realizes that beneath the different appearance, Loki is still the same person he cares about. They could go on a quest together where Thor has to protect Loki from Asgardians who don't trust the Jotun form.
A simple plot could be that Percy discovers a way to enter the world of Thor. Once there, he tries to prove himself worthy to lift Mjolnir. Along the way, he teams up with Thor and the other Asgardians to fight off a new threat that endangers both his world and Asgard.