His relationship with Annabeth would be very different. Annabeth might be initially scared of Percy because of his dark lineage. She would be cautious around him as she is used to the more 'typical' demigods. Percy, on the other hand, might feel isolated from her because he knows she is wary. His friendships with the other demigods at Camp Half - Blood would also change. Some might avoid him, while others might be intrigued by his new powers and origin. Grover, for example, might be torn between his loyalty to Percy and his fear of what Percy could become.
With the gods, Percy's relationship would be extremely strained. The Olympians would see him as a potential disruptor of the order they have maintained. Zeus might be especially hostile towards him, fearing that Percy could use his powers to overthrow him. Poseidon, who was his father in the original story, would be in a difficult position. He might not know how to react to Percy having such a different and powerful origin. Among the minor gods and goddesses, some might try to use Percy for their own gain, while others would stay away to avoid getting involved in the potential chaos that Percy could bring.
His relationship with Annabeth would be severely strained. Annabeth, who has always known Percy as Poseidon's son, would be confused and a bit distrustful. She might think Percy has been lying to her all this time. His friends at Camp Half - Blood would also be divided. Some would be scared of his new powers and his connection to Tartarus, thinking he could be a danger. However, some might be more understanding, especially those who have faced their own identity crises. His relationship with the gods would also change. The gods who were once somewhat friendly or at least neutral towards him might now see him as a threat. Zeus, for example, would be extremely wary of Percy's Tartarus - related abilities.
A plot twist could be that Percy has a connection to the primordial forces that even the Titans and the Olympians are afraid of. His link to Nyx and Tartarus means he can access parts of the universe that are normally off - limits. For instance, he might be able to open portals to the darkest corners of Tartarus, which could either be a great advantage or a huge danger. Also, he could have the power to call upon the creatures of the night created by Nyx, and these creatures could be either his allies or a threat to the existing order of the demigod world, depending on how Percy chooses to use his powers.
His relationship with Annabeth would definitely be affected. She might be a bit wary at first, since Nyx is such an unknown and powerful entity. But she would also be there to support Percy as he figures things out.
His powers would likely be much darker. He might have the ability to manipulate shadows like Nyx, using them to hide or even attack. And from Tartarus, he could have the power to cause earthquakes or open up chasms in the earth. He could also have a natural resistance to the harmful effects of the Underworld, such as the poisonous gases and the draining of energy that normal demigods experience.
One plot idea could be Percy struggling with his new identity. Since Tartarus and Nyx are such powerful and dark entities, Percy might have to battle against the dark urges within him. He could be shunned by his friends at first, but then prove that he's not defined by his parentage. For example, he might save Camp Half - Blood from a new, powerful threat using his unique powers that come from his heritage.
This is a really interesting concept. In the original Percy Jackson series, Percy is the son of Poseidon. But in this fanfiction idea, if he were the son of Gaea and Tartarus, it would completely change his character and the story. His powers would likely be much darker and more primal. He might have an in - depth connection to the earth and the abyss, which could lead to some really unique storylines.
In most traditional Percy Jackson lore, he is the son of Poseidon. However, in fanfiction, authors can create all kinds of alternate universes. So, it's possible for him to be depicted as the son of Gaia and Tartarus in some fan - created stories.
His relationships with his friends could become stronger. When he eventually gets out, his friends might see him as even more of a hero for surviving Tartarus alone. They could respect him more and he might be more confident in his relationships.
Percy's relationship with the other campers at Camp Half - Blood would be a rollercoaster. The children of Poseidon might feel a bit betrayed or confused, as they thought Percy was one of their own. However, Percy could use his new status to bridge gaps between different cabins. For example, he could work with the children of Aphrodite to improve relationships in the camp, since Hera has some connection to love and relationships in a different way than Aphrodite. With the gods, his relationship with Zeus would be extremely strained, given Zeus's past issues with Hera. But he might find new allies among the gods who are friendly with Hera, like Hephaestus. Overall, Percy's relationships would be a mix of challenges and new opportunities.
Developing his powers further is also a way. Since he's the son of Nyx, he could learn to manipulate different aspects of darkness like creating illusions using shadows or traveling through the dark realms faster. This would not only make him more powerful but also show his growth as a character as he masters these new abilities.