One big challenge could be competition among other researchers. In the fanfiction world, there could be rival marine biologists who want to be the first to discover something new. Percy might also face environmental threats. Things like pollution ruining the habitats he's studying or climate change affecting the behavior of the marine life he's researching. He'd have to find ways to work around these issues to continue his work.
Percy could face difficulties in getting permission to access certain restricted areas of the ocean. Maybe there are military zones or privately - owned areas that he needs to study. Another challenge could be dealing with the bureaucracy of the scientific community. He might have to jump through a lot of hoops to get his research approved or published. And of course, there's the challenge of working in a harsh and unpredictable environment, where weather conditions can quickly turn dangerous.
Well, I'm not sure of the exact titles, but generally in such fanfictions, Percy would be involved in things like coral reef conservation. Maybe in some fanfictions, he teams up with other characters to study the migratory patterns of whales. He could also be researching deep - sea organisms that are yet to be fully understood. You can search on fanfiction platforms using keywords like 'Percy' and'marine biologist' to find relevant works.
He may face challenges in the magical realm. The magic in the Percy Jackson universe might not interact well with his cyborg parts. For example, if he tries to use his powers while his cybernetic parts are active, there could be some unforeseen consequences. Also, he may be an outcast in both the human world (because he's a demigod) and the demigod world (because he's now a cyborg), which could lead to a lot of emotional and practical difficulties.
Plumbers often face the challenge of working in dirty and cramped spaces. Sewers and small utility closets are common work areas. Also, they have to keep up with new technology and building codes. For instance, new regulations about water conservation may require them to install different types of faucets or toilets, which they need to learn about quickly.
One challenge could be security. Given Harry's fame, there might be Death Eater remnants or nosy reporters trying to crash the wedding. They'd have to set up strong magical wards around the venue.
Naruto would face quite a few challenges. For one, his growth might be stunted as the team overprotects him. He could also face ridicule from outside the team who might see him as a weakling now. Moreover, he has to deal with the internal team dynamics where Sasuke may not be fully accepting of his new role and Naruto would have to prove himself constantly.
One major challenge would be Artemis's vow of chastity. Since she has sworn to be a maiden goddess, falling in love goes against her very essence. In the fanfiction, this could create a huge internal conflict for her, as well as external pressure from the other gods who uphold her vow.
One challenge could be that the connection between them is being blocked. Maybe some dark magic or a powerful enemy has created a barrier. So Percy has to find a way to break through this block just to get his call for help to Poseidon. Another challenge might be that Poseidon is preoccupied with his own problems in the underwater world, like dealing with a rebellion among his own sea creatures. So Percy has to convince Poseidon that his situation is also important.
One challenge could be dealing with jealous teammates. Since Percy is so talented in the water, some might envy his skills. Another is the pressure to always win. Everyone expects the team to do great with Percy as captain. Also, he might face difficulties in getting the team to work together if there are different personalities.
He might face internal conflict. Naruto has always been an open and honest person, so keeping such a big secret could go against his nature. This could lead to him struggling with his conscience. Also, he would need to balance his normal life with his secret Hokage duties without raising suspicion. For instance, he can't always disappear suddenly to attend to Hokage business without people getting curious.
One major challenge would be living up to the legacy of the original First Hokage. Everyone would have high expectations of him. Another challenge could be dealing with the political aspects of being in such a high - ranking position. He's used to being more of an out - of - the - box hero, not a traditional leader. Also, he might face resistance from some of the older clans in Konoha who have their own ideas about how the village should be run. And he would need to balance his new role with his relationships with his friends, who might see him differently now.