One major challenge could be the powerful and malevolent creatures that inhabit Tartarus. Monsters like the Titans or other ancient evils would try to stop him. They are much stronger than the usual foes he faces on the surface. Another challenge is the very nature of Tartarus itself. The place is designed to be inescapable, with its dark magic and chaotic environment constantly working against Percy.
In fanfiction, Percy would face the challenge of the ever - changing landscape of Tartarus. One moment there could be a bottomless pit, and the next, a wall of fire. He also has to deal with the psychological pressure. Being alone in such a desolate and terrifying place can wear on his mental state. And of course, there are the traps. Traps set by the gods or the primordial forces long ago to keep anything from escaping, and Percy has to figure out how to avoid or overcome them.
The environment itself is a big obstacle. Tartarus is a place of extreme darkness and chaos. It can mess with Percy's mind, making it difficult for him to focus on his training. The terrain is also treacherous, with rivers of fire and bottomless pits.
One of the main challenges would be the dangerous environment. Tartarus is filled with all kinds of monsters and hazards. Percy would constantly have to protect the child from these threats. Also, the lack of proper resources like food and clean water could be a huge issue. There's not much in Tartarus that is suitable for a growing child.
He might face the challenge of overtraining or undertraining. Since he doesn't have a coach or a training partner to tell him when he's doing too much or too little, he could end up either exhausting himself or not making enough progress. In fanfiction, he could also struggle with loneliness. Training by himself means no one to share his frustrations or small victories with. This loneliness could potentially affect his mental state and in turn, his performance. Additionally, without feedback from others, he may develop bad habits in his training that could be hard to correct later on.
One challenge could be dealing with the trauma. Tartarus is a terrifying place, and Percy might have nightmares that disrupt his school life. He could also find it hard to relate to his classmates who have no idea what he's been through.
He could also face challenges related to the knowledge required to use his power effectively. In fanfiction, there might be ancient texts or prophecies that he needs to decipher in order to fully understand and utilize his new powers. But these texts could be written in a long - lost language or be guarded by powerful entities, making it difficult for him to access the necessary information.
One challenge could be the time - warping effect of the casino. Time moves differently there, and Percy has to fight against getting caught up in it himself while trying to find Nico. Another might be the various distractions, like the all - you - can - eat buffets and the never - ending games that are designed to keep people inside.
He might face mental challenges like PTSD. Tartarus is a horrible place, and the things he witnessed there could haunt him.
In some fanfictions, Percy might use his water - controlling abilities in unique ways. He could manipulate the rivers of Tartarus, like the Phlegethon, to create distractions or even use the power of the water to propel himself out. Maybe he also forms alliances with some minor creatures in Tartarus that are not as hostile as the main threats and they help him find a hidden passage.
One challenge could be mastering the balance between different elements. Each element has its own characteristics, and it's not easy to control them all harmoniously.
One challenge could be the strength of the enemy. If the enemy is very powerful, it would be difficult for Aang to overcome them alone. Another challenge might be the lack of resources. He may need certain items or help from others to save the Airbenders but not be able to get them easily.