You can start by looking on fanfiction.net. It has a large collection of fanfictions for various fandoms, including Percy Jackson, and you might find some great stories about Percy and Leo there.
There's 'Leo and Percy's Adventure' which focuses on their shared experiences and how they start to see each other in a different light. It's full of action and some really sweet moments between them. In this fanfiction, their personalities complement each other well.
One of the most exciting things about their bromance in fanfiction could be their combined skills during a quest. Leo's mechanical genius and Percy's water - controlling abilities would make for some really cool and unique battle scenes. For example, Leo could create a complex mechanical device to cross a dangerous terrain, while Percy uses his powers to keep the device afloat or to fend off water - based monsters.
Emotionally, they support each other through understanding. They both have their own insecurities. Percy sometimes doubts his leadership skills, and Leo has his own issues with feeling like he belongs. By sharing their feelings, they are able to comfort and encourage each other, which is a big part of their bromance in fanfiction.
One popular Percy Jackson and Leo Valdez slash fanfiction is 'Flames of Friendship'. It delves deep into their relationship, exploring how their different personalities complement each other. Another one could be 'Shared Journeys' which takes them on an adventure together that tests their bond and also shows their growing affection in a really engaging way. And 'Hidden Feelings' is also quite good as it focuses on the more emotional side of their relationship, with some really well - written internal monologues.
To write a Percy Jackson and Leo Valdez slash fanfiction, you need to be familiar with the 'Percy Jackson' universe. Research the settings, the other characters around Percy and Leo. When writing their relationship, make it believable. You can't just jump into a romantic relationship right away. Let it develop slowly. Maybe start with a common goal they have, like saving a camp. As they work towards it, show their mutual admiration. Also, use vivid descriptions. Describe how Percy looks when he's near water, or how Leo's eyes sparkle when he's working on a new invention.
One great Percy Jackson and Leo Valdez fanfiction is 'The Adventures Beyond Camp Half - Blood'. It combines their unique skills and personalities really well. The story takes them on a quest where they have to work together to defeat an ancient monster. The author does a great job of capturing the essence of both characters.
I don't think the gods read Leo Valdez fanfiction. Gods in that universe are often busy with more important things. They have to manage their powers, deal with other gods, and look after the affairs of the demigods. Fanfiction is a form of human creativity, and it's not something that would likely be on the gods' radar. It's more of an entertainment for the fans of the Leo Valdez stories.
One common theme is the exploration of their characters in a new light. Since they are both heroes in the original series, in fanfiction, their relationship might be explored as they support each other in different ways than just as friends. Another theme could be acceptance, both within themselves and from the demigod community.
I really liked a fanfic called 'Fire and Water'. It delved deep into the relationship between Leo and Percy. It showed how their different powers could work together in a really creative way. There were some great action scenes and also some really touching moments of friendship. It was a long read but definitely worth it as it explored the characters in depth and took them on a journey that was both exciting and full of character growth.