Some fanfictions might explore the idea of Percy being the only hope to stop an ancient evil from escaping Tartarus. He might have to traverse through the different levels of Tartarus, each with its own set of challenges. On one level, he could face a horde of undead warriors, and on another, he has to solve complex puzzles to progress. Along the way, he could also learn the true origin of Tartarus and how it relates to the entire Greek mythology world.
Well, a great plotline might be Percy's struggle with his own inner demons while in Tartarus. He could be haunted by his past failures and the fear of not being able to save his friends. This internal battle could be paralleled with his physical battles against the terrors of Tartarus. Also, there could be a plotline where Percy discovers a long - lost power within himself that is the key to either ruling Tartarus or escaping it.
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.
A third plotline could be Percy's search for a powerful artifact or knowledge in Tartarus that could help him in his future battles or save his friends. Along the way, he discovers secrets about the origin of the gods or the true nature of Tartarus itself, which changes his understanding of the world he thought he knew.
In some fanfictions, Percy's torture in Tartarus could be part of a grander scheme. For example, an enemy on the surface world has made a deal with the forces of Tartarus to weaken Percy. As he endures the torture, he gradually uncovers the conspiracy and tries to find a way to not only escape but also stop those who sent him there. His friends, unaware of his situation at first, start to suspect something is wrong and embark on a quest to find out what happened to him and rescue him.
Perhaps there's a plotline where Percy discovers new and dark powers within Tartarus that he has to learn to control. This could lead to him having to make difficult choices about whether to use these powers for good or risk being consumed by them. He may also encounter other fallen or corrupted beings that either try to help or hinder him on his journey.
Some Tartarus fanfictions focus on Percy's mental state while in Tartarus. It could explore his nightmares and how he copes with the overwhelming sense of despair. For instance, he might have visions of his friends and family in danger back on the surface, and he has to find the strength within himself to keep going in the face of such mental torture.
Well, a plotline could be Percy having to adapt to the extreme and harsh environment of Tartarus. The place is full of darkness and danger. He might have to learn to harness the strange and dark energy that exists there in order to defend himself. There could also be a plot where Percy is forced to make difficult choices. For instance, he might be presented with an option that could save him but at a great cost to others. This would test his moral compass and show how much he has grown as a character in this extreme situation.
One interesting plot could be Percy's struggle to control his new powers as the God of Tartarus. He might face challenges from other gods who are threatened by his rise. Another could be his journey to reform Tartarus, making it less of a hellish place. For example, he could try to bring some order to the chaotic entities that reside there.
A great plot could involve Percy finding a way to use the unique environment of Tartarus to his advantage. For example, there could be some sort of energy in Tartarus that he discovers he can harness to become stronger, but it has a dangerous side - like it might slowly corrupt him. He then has to struggle with the decision of whether to keep using it to get out or resist it.
One possible plotline could be Percy having nightmares about his time in Tartarus. He might struggle with PTSD, which could affect his relationships with his friends and family at Camp Half - Blood. Another could be that he brings back some sort of dark power or knowledge from Tartarus that he has to figure out how to control or use for good. Maybe he discovers a way to close the entrance to Tartarus permanently so that no more monsters can come out and endanger the demigod world.
One interesting plotline could be their struggle against the various monsters in Tartarus. For example, facing off against the giants or other terrifying creatures that lurk there. Another could be their search for a way out while dealing with the psychological toll of being in such a dark and desolate place.