One possible plot could be Percy getting a special power from Apollo's blessing. For example, he might gain the ability to heal faster, which would be really useful in his battles. He could use this new power to save his friends in a dangerous situation, like when they are facing a powerful monster and his friends are severely injured.
A third plot could be about Percy having to fulfill a task given by Apollo as a result of the blessing. This task might be related to saving a temple of Apollo that's being threatened by an ancient evil. Along the way, Percy discovers more about Apollo's past and how his blessing is not just a gift but also a heavy responsibility that could change the fate of the entire demigod world.
Another plot could revolve around the relationship between Percy and the Apollo cabin. Since he's blessed by Apollo, there could be some sort of alliance or special connection. Maybe the Apollo kids teach Percy some of their skills, like archery or prophecy. This could lead to Percy having to make a choice between his loyalty to his own cabin and his new connection to the Apollo cabin.
One interesting plot could be Percy using the blessing of Hestia in a battle against a powerful monster. Maybe the blessing gives him the ability to control fire in a unique way, like creating protective barriers of flames that the monster can't penetrate.
One interesting plot could be Percy getting a new and extremely powerful ability blessed by a previously unknown god. This could lead to him having to face a new set of challenges and enemies that are specifically drawn to his new power.
Well, one interesting plot could be Percy getting new and extremely powerful abilities due to the chaos blessing. This might make him an even greater hero, facing off against more dangerous foes. For example, he could have the power to manipulate the very fabric of reality in small ways.
One interesting plot could be Percy using his water powers in a new way due to his connection to Apollo. Maybe he can heal with water in a more effective way. Another plot could involve Percy and Apollo's other siblings having to team up to fight a new, powerful enemy that threatens the gods and demigods alike. For example, a primordial being awakening.
Well, a plot could be that Percy is kidnapped by a sorcerer who has a vendetta against Poseidon. The sorcerer thinks that by taking Percy, he can get revenge on the sea god. Another could be that some jealous demigods from another camp, who feel overshadowed by Percy's fame, kidnap him. They might try to make him look bad in front of the other demigods. Also, it could be that a mysterious force from the Underworld kidnaps Percy because they fear his growing power and want to keep him out of the way.
One possible plot could be Percy being stuck in a time loop where he has to keep saving Artimis from a recurring threat. Maybe a powerful Titan is constantly finding new ways to capture her, and Percy has to figure out the pattern within the loop to stop it for good. Another idea is that the time loop is a result of a curse placed on Artimis, and Percy has to team up with the hunters of Artimis to break the curse before the loop consumes them all.
There could also be a plot where the sirens are not the typical villains. In this fanfiction, they could be victims of a greater evil in the ocean. Percy has to team up with them to fight this common foe. It would be a great twist on the traditional view of sirens in the Percy Jackson universe.
The blessing could make Percy more confident. Knowing that a major god like Apollo has blessed him gives him an extra boost. He might take on more challenges without hesitation, believing that he has the favor of the gods on his side.
In some fanfictions, Typhon is not just a mindless monster. He might have motives and desires. For instance, he could be seeking revenge against the gods for imprisoning him. This makes him a more complex character and gives the story more depth. Writers can then explore the moral implications of whether the demigods should just destroy him or try to reason with him.
One interesting 'Percy Jackson and Apollo fanfiction' story could be about Apollo teaching Percy some new musical skills related to his powers. Since Apollo is the god of music and Percy has his own unique abilities, their interaction in this aspect can be really fascinating.