A big theme is also about power and responsibility. As a mercenary, Percy has power in his skills and abilities, but he also has the responsibility to use them for good. In many fanfictions, he struggles with how far he can go in his mercenary work without compromising his values. For example, he might be offered a large sum of money to do something that goes against his moral code, and how he deals with that is a central part of the story. This theme is explored in different ways in different fanfictions, sometimes more subtly and sometimes more directly.
The theme of powerlessness is quite common in 'percy begs pjo fanfic'. Percy, who usually has some level of control in the main series, is now in a position where he has to beg. This shows that there are forces or situations that are beyond his normal ability to handle. And there's also the theme of hope, as his begging could be a last - ditch effort to find a solution to a seemingly impossible situation.
One common theme is adventure. Percy is always going on some sort of journey or quest. Another is friendship, as he relies on his friends like Annabeth and Grover. And of course, there's the theme of power, especially related to Percy's unique abilities which might be emphasized more in fanfics about his tail.
Yes, there are several. Some focus on exploring how Percy's life would be different if he was born a monster. For example, in some fanfics, his relationships with other characters are completely reimagined. He might face more prejudice or have to find new ways to fit in the world of demigods and monsters.
Grover would be a bit more cautious. He might be a bit scared of the Norse monsters at first. But as he reads more, he'd start to see the similarities between the Norse and Greek worlds in terms of how nature is involved. He might notice how the Norse also have a connection to the natural world, like the wolves and the trees, and how it compares to his own connection to nature in the PJO universe.
Percy would probably find it hilarious. He has a good sense of humor and would likely enjoy the wild and crazy scenarios fans come up with. He might even share the funnier ones with his friends at Camp Half - Blood.
Some characters might be flattered. Like Percy, he could be happy to see that people are so interested in his story in 'The Son of Neptune' that they write fanfiction about it.
Perhaps it's a curse or a spell gone wrong. In the world of PJO, there are many magical mishaps. It could be that someone intended to harm Percy and this was the result. Or it could be a side - effect of a powerful artifact he came into contact with.
If Percy is exiled in this PJO Avengers fanfiction, it could lead to some really interesting story developments. Since he's used to having his friends and allies around in the Percy Jackson series, being alone in the Avengers' world would be a big change. He might start to discover new powers or abilities as he struggles to survive. And there could be a whole plot about him trying to prove his worth to the Avengers so he can be accepted back.