Perhaps the antagonist could be a corrupted demigod. Someone who was also in Tartarus, but instead of coming out stronger in spirit like Percy, they were twisted by the darkness there. They now want to bring that same darkness to the world of the demigods and see Percy as the main obstacle to their plans.
Perhaps he could make an alliance with some of the less hostile creatures in Tartarus. There might be beings who are also tired of the chaos and want to help Percy in exchange for something, like a promise to free them from Tartarus if he ever gets the chance. Percy is known for his charisma and ability to make friends, even in the most unlikely situations.
In some fanfictions, Percy Jackson might be depicted as dying in Tartarus. However, this is a departure from the original series. Fanfiction writers often take creative liberties, and some may choose to create such a tragic scenario for shock value or to explore different themes like sacrifice and the finality of death in a harsh, mythological setting.
Well, one aspect to consider in this fanfiction could be the character development. Percy Jackson is already a well - established character, but as the heir of Tartarus, he might face new challenges that force him to grow in different ways. Maybe he has to deal with darker powers within himself. Another point could be the world - building. Tartarus is a very dark and dangerous place in the Percy Jackson universe, so how the author expands on that and shows its influence on Percy and the story is important. Also, the relationships with other characters would be interesting. Will his friends still trust him when they find out he has this new 'heir' status? How will his enemies react?
Another plot could be that something from Tartarus has followed Percy out. A small, malevolent creature that starts causing trouble in Camp Half - Blood. Percy feels responsible for it and has to find a way to send it back to Tartarus without putting everyone in danger.
In some fanfictions, Percy might be more withdrawn. He has seen the horrors of Tartarus and it could make him less trusting of the world around him. He may also have new powers or a deeper understanding of his abilities that he gained from the experiences there.
In a fanfiction of Percy Jackson dipping in the Styx in Tartarus, it might explore the idea of him getting new powers or a stronger connection to his godly side. For example, his water - controlling abilities could become more refined and he could have a better understanding of the Underworld's waters. Also, he could encounter some long - forgotten spirits or creatures that guard the Styx in Tartarus.
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.
Well, in many fanfictions, Percy might be on a mission to assassinate some powerful being in Tartarus. Maybe he has to face all kinds of hellish creatures and overcome insane challenges. It could involve him using his water powers in unique ways, like creating weapons out of water to fight the demons of Tartarus.
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.