There are several possible consequences. Percy may find himself isolated as other characters might be afraid to get too close to him due to Zeus's possessiveness. His growth as a character could be stunted as Zeus tries to mold him according to his own desires. It could also spark a rebellion among the demigods who don't want Zeus interfering so much with one of their own. Moreover, the relationship between the gods could become more complex and tense, especially between Zeus and those who support Percy's independence, like Poseidon and Athena.
The consequences can be quite significant. For starters, Percy's relationships with his friends could be strained. His friends might be worried about Zeus's influence over him. Percy himself could start to resent Zeus's possessiveness, which might lead to him acting out. In the larger context of the fanfic's world, it could also cause an imbalance in the power dynamics among the gods. If Zeus is too focused on Percy, other important matters in the divine realm could be neglected, leading to chaos.
In some fanfics, Zeus might be possessive of Percy because Percy represents a powerful force or potential. Zeus, being the king of the gods, wants to control all sources of power. Percy's abilities and his role in the demigod world could make Zeus see him as something to be owned or at least controlled.
In such a fanfic, one possible consequence could be a major upheaval in the world of the story. The child would be of divine and demigod lineage, which might attract all kinds of unwanted attention from other gods and mythical beings. It could also lead to a power struggle as different factions might try to use the child for their own purposes.
One consequence could be Percy losing his human connections. His relationships with his friends and family were based on his shared humanity. As a god, he might find it hard to relate to them in the same way. For example, his mortal friends may age and die while he remains an immortal god, leading to a sense of isolation.
One possible consequence is that it could lead to a split in their group. If they are part of a team or a community, their animosity could cause others to take sides, creating factions.
For the demigods, things could change a lot too. Percy is a champion of the demigods, and his victory over Zeus might mean better treatment for demigods. They could be more respected and have more rights in the world of gods and mortals. However, it could also make them targets of those who are against Percy's actions.
It could also be about power. Percy might realize that with Zeus out of the way, he can reshape the world of the gods in a more just and fair way. He could believe that Zeus's rule is corrupt and that killing him is the only way to bring about real change.
One possible implication is that it could influence how Zeus views the modern world's perception of the mythological characters. If he likes Percy fanfiction, he might be more open to the new interpretations and ideas that fans have about the whole demigod concept.
The story of Percy and Zeus' friendship could begin with Percy being summoned to Olympus. Zeus has been observing Percy for a while and is intrigued by his abilities. At first, there is tension between them. But as they are forced to work together on a mission to retrieve a lost and powerful artifact, they start to see each other in a new light. Percy shows Zeus his loyalty and Zeus offers Percy protection. This newfound friendship gradually changes the dynamic between demigods and gods, leading to a more harmonious co - existence.
A fanfic about Percy, brother of Zeus, could start with Percy feeling a sense of isolation. Despite being part of the divine family, he doesn't quite fit in. He decides to leave Olympus for a while and explore the mortal world. There, he experiences the joys and sorrows of humanity in a way that Zeus never has. He falls in love with a mortal, which causes a huge rift between him and Zeus. This love story could be the central theme of the fanfic, with Percy having to choose between his family and his new - found love.
It's possible that in the fanfiction, Zeus made a deal that put Percy or his loved ones in danger. For instance, Zeus might have made an agreement with an enemy just to maintain his own power, without considering the consequences for Percy and those around him. This would surely make Percy hate Zeus.