Maybe some rogue demigods who are power - hungry. They see Percy's new title as Champion of Ouranos as a way to gain ultimate power. So they would try to either take the title from him or prevent him from using his powers. They could form a secret group and plot against Percy, using their own demigod abilities and knowledge of the demigod world to their advantage.
A great plot for this fanfiction could be Percy being summoned by the spirit of Ouranos himself. Ouranos could give Percy a task to unite all the different factions of demigods, including those who are usually at odds with each other, like the Romans and the Greeks. This would be a huge challenge as there are old grudges and differences in beliefs. Along the way, Percy would have to overcome his own doubts and the mistrust of others. He might also face some magical obstacles that are specifically designed to prevent the unification of the demigods, and he has to use his wits and powers as the Champion of Ouranos to break through them.
Well, in fanfiction, if Percy is the Champion of Pontus, his story would be filled with more mystery. Pontus is an ancient and powerful entity. Percy might be called upon to do things that go against the traditional ways of the Olympian - influenced world he's used to. He could discover secrets about the origin of the sea and his own powers that were previously unknown. This would not only make for an exciting read but also show how Percy can adapt and make his own path even when given a very different role.
One possible fanfiction could be about Percy Jackson seeking the guidance of Hestia, the goddess of the hearth, who has now become a champion in some way. Maybe she is a champion against a new threat to the demigod world. Percy could learn new skills or gain unique powers from her. For example, powers related to home and family, which could be used to protect Camp Half - Blood in a different way than before.
In fanfiction, Percy Jackson as the champion of Hades could bring a whole new dynamic. He might have to deal with the darker aspects of the Underworld. For example, he could be in charge of ensuring the souls are properly sorted, which is a huge responsibility.
In some fanfiction, Percy Jackson might be depicted as a champion of Kronos, but this goes against his character in the original series. In Rick Riordan's official books, Percy is a hero who stands against Kronos and his evil plans.
In Percy Jackson fanfiction, the 'Champion of the Sun' could be a character with special powers related to the sun. It might be someone who has the ability to control sunlight, perhaps for combat or to perform other extraordinary feats. Maybe they are a hero figure within the fan - created story, with a backstory that ties them to the sun in some way, like being blessed by a sun - related deity.
The allure lies in the fact that Percy already has a very interesting backstory. As the Champion of Poseidon, fanfiction writers can expand on his powers and his place in the mythological world. For instance, he could be sent on quests that are specifically related to Poseidon's domain, like protecting a sacred sea temple from an ancient evil.
One possible plot could be Percy's discovery of his true parentage. He might struggle with the implications of being the son of two powerful primordial deities. For example, he could face a conflict between the forces associated with Ouranos and Gaea. This could lead to him having to make difficult choices about which side to support, if any. And he may also have to deal with the reactions of his friends and the other demigods who might view him differently now.
Well, it could mean a huge power shift in the Percy Jackson universe. Percy already has a lot of power, and absorbing Ouranos might make him almost god - like. It could also lead to new conflicts, as other characters might fear his newfound strength or try to use it for their own gains.