One interesting plotline could be Percy's struggle against the various monsters in Tartarus. He might have to use his wits and powers in new ways to survive. Another could be his journey to find a way out, perhaps making unexpected alliances with other beings trapped there.
He could find some minor gods or goddesses who have been banished to Tartarus. They might see Percy as a way to get revenge on the Olympians or simply a means to escape. Another potential ally could be some of the more intelligent monsters, like a centaur who has been there for a long time and has knowledge of the place.
In some fanfics, Nico di Angelo could be the one to help Percy. Since Nico has a connection to the Underworld and has some dark powers, he might be able to enter Tartarus more easily than others. He could use his powers to fend off the monsters and guide Percy to safety.
He might face terrifying monsters. Tartarus is full of the most dangerous creatures in the Percy Jackson universe. So he'd have to fight for his life constantly.
One possible plot could be Percy having to face his inner demons in Tartarus. Maybe he has to battle new and terrifying monsters that are unique to that realm. He could also encounter old foes who have been made even more powerful in Tartarus.
In fanfiction, if Percy Jackson is sent to Tartarus, he might face countless deadly monsters. Tartarus is a really dangerous place. He would have to use all his skills and powers to survive. Maybe he'd meet some old foes there, and it would be a great test of his courage and determination.
If Percy Jackson is sent to Tartarus in fanfiction, it could be a harrowing experience. First off, the environment itself is a nightmare. The terrain is dangerous and full of pits and lava. Percy would have to rely on his wits as much as his strength. Since Tartarus is the prison for the most powerful Titans and monsters, he'd be up against foes far more powerful than he's used to. He might even discover some long - lost secrets about his powers or his family's past while trying to find a way out.
He might use his sword skills and his ability to control water. For example, he could create shields out of water to protect himself from attacks. He would also try to find any weaknesses in his enemies. If there are any water sources in Tartarus, he could use them to his advantage, like making geysers to distract or attack his foes.
One possible plotline could be Percy's struggle for survival in Tartarus. He might face various terrifying monsters and have to use his wits and powers to stay alive. Another could be his journey of self - discovery in that dark place, realizing new aspects of his abilities or his past. Maybe he also tries to find a way to escape Tartarus while also dealing with the psychological toll of being in such a desolate and dangerous realm.
Perhaps one of the Titans who were banished to Tartarus. They might see Percy as a threat to their plans of revenge or escape. Kronos, if he still has some form of existence in Tartarus, could be a major antagonist. He would have his own motives and powers, and he could try to manipulate Percy or simply get rid of him.