Another aspect that makes a good 'The Lightning Thief' fanfiction is the exploration of relationships. This could be the friendship between Percy and his friends, or a new romantic relationship. Fanfictions that delve deeper into how the characters interact with each other on an emotional level can be really captivating. Also, a good fanfiction might introduce new mythological elements that blend well with the existing Percy Jackson universe, like a new type of monster or a different take on an old god.
Well, another place could be Wattpad. There are many users on Wattpad who write fanfiction, and it's likely that you'll find some interesting 'The Lightning Thief' fanfiction there. Also, some Tumblr blogs are dedicated to sharing and discussing fanfiction of this series. You might want to explore Tumblr as well.
Perhaps he's just curious. He wants to see how other fans are interpreting the world he's a part of. It could be a way for him to feel more connected to the fan community.
The page count for the Lightning Thief graphic novel isn't fixed. Usually, it's somewhere in the range of 220 to 280 pages, but this can change based on factors like the size of the book and the layout.
One popular website could be Archive of Our Own (AO3). It has a large collection of fanfics for various fandoms including 'The Lightning Thief'. Another option might be FanFiction.net. There you can find different interpretations and stories related to the book series.