Sasuke could be Naruto's parkour mentor. Despite their past differences, Sasuke has great skills in movement and agility. He could teach Naruto more refined parkour techniques, like how to land more quietly or how to make sharper turns while running on rooftops.
The Sound Ninjas could be great antagonists. They could use their own unique parkour - like skills to try and stop Naruto. They might be chasing him through the forest, and Naruto has to use his parkour skills to outmaneuver them.
One idea could be Naruto using his parkour skills to escape from Orochimaru's lair. He jumps from tree to tree, wall - runs along the cave walls, and uses his ninja agility in a new and exciting way.
It's popular because it combines two exciting elements. Percy Jackson's world is full of adventure and his character has a lot of fans. Parkour is a really cool and dynamic activity. So when you put them together, it creates a new and interesting scenario for fans to explore.
Well, in these fanfictions, it's fascinating to see how parkour can give Peter an edge in his superheroics. He can reach places faster and in more creative ways. Also, it often shows a different side of Peter, like his determination to master a new skill outside of his spider - powers. And the action scenes are really intense when he's using parkour while fighting crime or just getting around the city.
You can try looking on fanfiction websites like FanFiction.net or Archive of Our Own (AO3). They have a large collection of fan - created stories, and you might be able to find some 'Harry Potter does parkour' fanfictions by using their search functions.
A great plot could be Naruto is sent on a mission in a foreign land full of tall buildings and narrow alleys. He has to use parkour to chase a rogue ninja through the city. Since he's not familiar with the terrain, he has to quickly adapt his parkour moves. For example, he might have to use his shadow clones to create distractions while he makes risky jumps from rooftop to rooftop.
One popular 'Peter Parker does parkour' fanfiction is 'Spidy on the Run'. It has some really cool action scenes where Peter uses his parkour skills to chase down bad guys in a very creative way.
A possible interesting plot could be Naruto discovers a hidden ninja village where parkour is the key to unlocking ancient secrets. He has to master new parkour skills to traverse the village's dangerous terrains filled with traps and challenges, all while facing off against a rival ninja group who also wants the secrets.
It could be a rogue ninja who has mastered parkour to an extreme level. He uses his skills to steal important ninja artifacts and Naruto has to stop him. This antagonist would be very fast and agile, making it difficult for Naruto to catch him using normal ninja techniques.