In a fanfic, Percy could have a mental battle with Gaea where the lemon plays a key role. Imagine Percy enters Gaea's mind - realm. There, he finds a withered lemon tree. By using his willpower and connection to the ocean (as water is also related to life like the lemon), he tries to revive the tree. As he does this, Gaea is forced to watch and is affected by his actions. If he succeeds in making the tree bloom again, it could signify his victory over Gaea's destructive plans.
Well, it's not as popular as some other pairings in the Percy Jackson fandom. Gaea is a major antagonist in the series, and the idea of her in a romantic relationship with Percy is rather unorthodox. So, compared to more common pairings like Percy and Annabeth, it has a much smaller following.
Gaea Science Fiction could be about various things. It might be about scientific concepts set in a fictional world related to Gaea. For example, it could involve stories of advanced technology, space exploration, or strange new species all within the context of a Gaea - themed universe.
I'm not sure specifically what that particular fanfiction is about as there could be many different interpretations. It might involve Naruto having some sort of connection to Gaea, perhaps in an alternate universe where Gaea is his mother and it could explore how his character develops with this new origin story, like new powers or relationships.
There might be a fanfiction where Percy forms an unlikely alliance with Gaea. Maybe Gaea is not entirely evil in this story, and they have to work together to face a greater threat that endangers both their existences. This would be a really interesting take on their relationship.
One great 'Percy Jackson Gaea' fanfiction is 'The Battle Against Gaea's Wrath'. It continues the story after the end of the main series, with Percy and his friends facing new threats related to Gaea. The author does an amazing job of keeping the characters' personalities intact.
One possible fanfiction could be about Percy Jackson having a strange encounter with Gaea's power while in a lemon grove. Maybe the lemon trees are enchanted by Gaea, and Percy has to figure out how to break the spell without getting caught in Gaea's grander plans for chaos.
In the Percy Jackson series, Gaea is a villain, and a love relationship between Percy and her in the context of the original story is very unlikely. However, in the world of fanfiction, anything can be created. There might be some fanfictions exploring such a strange and dark concept, but it would be a very unorthodox take on the characters.
A common theme is redemption. Many fanfictions explore the idea of Gaea being redeemed through her interaction with Percy. Since Percy is often seen as a symbol of hope and goodness in the original series, his influence on Gaea can be a way to show that even the most malevolent beings can change.
One common theme is identity struggle. Since Percy is known as Poseidon's son in the original lore, being the son of Gaea in fanfic is a huge shift. He has to figure out who he really is. Another theme is power. With Gaea as his mother, he might have different powers, and how he uses or controls them is often explored.