It could be really interesting. Maybe Naruto would sing 'Numb' as a way to show his frustration with the expectations of the village. The lyrics of the song might mirror his feelings of being trapped in a system he doesn't fully understand.
Yes, there might be. The Naruto fandom is quite large and diverse, so it's possible that some fans have created fanfiction where Naruto sings 'Numb'. You can try searching on fanfiction websites like FanFiction.net or Archive of Our Own to find such works.
Percy is likely to be a shell of his former self, numb and withdrawn. He might not show the same bravado and charm as in the original stories. His friends, like Annabeth, would be worried about him and try to draw him out. Annabeth could be very determined to get Percy back to his old self, using her intelligence to figure out what's wrong.
First, decide which two (or more) universes you want to cross. For example, if it's Numb3rs and a superhero universe, think about how the math skills from Numb3rs can interact with the superpowers. Then, create a basic plot. Maybe the superhero is having trouble with a villain who uses math - based traps, and the Numb3rs characters come to the rescue.
In the fanfiction, the numbness could be a result of Percy being betrayed by someone close. He shuts down emotionally, not knowing who to trust anymore. He starts to isolate himself, but then through a series of events, he realizes that not everyone is against him. His journey back to trusting and feeling again could be filled with self - discovery and new friendships within the demigod community.
The story could start with Charlie being taken suddenly, like when he's leaving the university. His brothers would be frantic. FBI would get involved quickly. They'd start looking at security camera footage around the area. If the kidnappers are smart, they'd cover their tracks well, but Charlie would leave clues, like scratching a math symbol on the floor of the vehicle he's in, which his brothers would eventually figure out.
In such a fanfiction, perhaps Charlie's brothers would use their skills to track him down. Donnie might use his technological know - how to analyze any digital trails left by the kidnappers. Meanwhile, Alan could provide moral support and also help by recalling any details about people who might have a grudge against Charlie.
Well, it could be a fan - created story where JK from BTS is going through a period of having a numb feeling. Maybe it's about his struggle to connect with his emotions. It could be set in the context of the high - pressure K - pop world where he's constantly under the spotlight and has to deal with so many things that gradually make him feel numb. It might also involve his relationships with other members or with some fictional characters in the fanfic.