They could fight due to a prophecy. If there's a prophecy that involves one of them being the 'chosen one' and the others think they should be, it would create a lot of tension. For instance, if the prophecy says that only one of them can save the world from a certain doom. Percy, being the main character in many stories, might be assumed by the others to be the one, but Thalia and Nico may believe they have just as much right. Their struggle for that role could lead to a fight. And during the fight, they would use their unique abilities. Percy would call upon the water, Thalia would summon her lightning bolts, and Nico would raise the dead to fight on his behalf.
Another reason could be different loyalties. Thalia has her own group of friends and allies, and Percy has his. There could be a situation where their friends' actions or needs put them at odds with each other. For example, if Percy's friends get into trouble with something related to Thalia's friends' territory or interests, it could spark a fight.
In a fanfic about Percy and Thalia's fight, it could start because of a misunderstanding. Maybe Thalia thinks Percy is getting too much attention from the gods and she's jealous for the sake of all the half - bloods. Percy, on the other hand, might not understand why Thalia is so hostile all of a sudden.
In a fight between Percy and Thalia in fanfiction, I think it would be a draw. They both have such strong wills and powerful abilities. Percy's connection to water and his combat skills with Riptide are formidable. Thalia's lightning powers and her skill with her spear are equally impressive. They also respect each other deep down. So, even if they started fighting, I think they would eventually realize that they're on the same side and stop before one of them could truly win.
Well, it could be about a misunderstanding. Maybe Percy accidentally uses his powers in a way that Thalia misinterprets as a threat to her leadership among the demigods. So she lashes out at him, and Percy, not one to back down easily, fights back.
In Percy and Thalia lemon fanfic, Percy and Thalia often have their characters explored in unique ways. Usually, their relationship might be depicted with more depth and complexity than in the original works. For example, their interactions could be centered around some special adventures where they rely on each other more. This kind of fanfic may also play with their individual powers and how they complement each other during difficult situations.
Thalia might be more likely to win. She has years of experience being on her own and fighting monsters before she joined the group. She is also a very tough and determined fighter. Her ability to call upon lightning is a very destructive power. Percy, while powerful, can sometimes be a bit impulsive in his fighting, which Thalia could use to her advantage to outmaneuver him and land a decisive blow.
A fanfic that stands out is 'The Trio's Trials'. This one is interesting because it not only focuses on their physical adventures but also their emotional growth. We see Percy dealing with his leadership role, Thalia coming to terms with her past, and Nico learning to open up more. The character development throughout the story is quite engaging.
The popularity of 'Percy and Thalia fanfic' comes from the fact that they have a deep connection in the original stories. People are curious about what could happen between them outside of the main plot. Writers can play with their friendship, create new adventures for them, and develop their characters further. It gives fans a chance to see different sides of Percy and Thalia that might not be shown in the official books.
I really like 'Percy and Thalia's Adventure'. In this fanfic, they go on a quest together that was not part of the original books. The author does a wonderful job of capturing their personalities. Thalia's fierce and independent nature and Percy's loyalty are shown really well throughout the story.