Percy is a resourceful character. He could use his knowledge of Greek mythology to find a way out. For instance, if there are any ancient spells or curses in the place where he is held captive, he might be able to reverse them or use them to his benefit. Also, his loyalty to his friends and the cause he believes in gives him the strength and determination to keep looking for a way to escape. He may endure hardships and keep his mind sharp, waiting for the perfect moment to break free from Luke's clutches.
Well, it depends on the specific fanfiction. Sometimes, Percy might get help from an unexpected source. He could befriend a magical creature that is also held captive by Luke and together they come up with an escape plan. He might also discover a hidden passage or weakness in Luke's lair that he can use to his advantage. Another possibility is that his friends from Camp Half - Blood somehow find out where he is and stage a rescue mission.
There's a possibility that a new, unknown and powerful monster could be the captor. This monster could be a hybrid of different mythological creatures, created by some dark magic. It has heard of Percy's fame and power and wants to keep him captive either to study him, or to use his power to become even more powerful itself. It could have a lair in a hidden and dangerous place, like an underground cavern filled with deadly traps.
Percy often gets angry at first. He's not the type to just take it lying down. But he also feels a bit confused as to why Luke is being so mean. Sometimes he tries to stand up to Luke, but other times he just withdraws into himself, feeling sad and alone.
Percy might use his water powers. He could manipulate water to create a distraction for Luke, like making a big wave or a water spout. Then, while Luke is distracted, Percy could quickly grab Annabeth and get her to safety.
One plot idea could be that Percy is held captive by an ancient, forgotten sea deity who wants to use Percy's powers for its own dark purposes. Maybe this deity has the ability to manipulate water in ways that even Percy hasn't seen, and he has to find a way to outwit it using his wits and the limited power he can access while captive. Another idea is that he's held captive by a group of rogue demigods who believe Percy is a threat to their new world order. They try to brainwash him into joining their side.
In the fanfiction, Percy could potentially control Typhon with the help of his friends. They could all work together, each using their own unique abilities. Annabeth could provide the strategic plans, while Grover could use his nature - related powers to distract Typhon. Percy, with his water powers, could then take advantage of the situation and subdue Typhon. It's all about teamwork and using their combined skills to handle such a powerful enemy.
He might use his superhuman strength and speed, which he has as a demigod. With his enhanced physical abilities, he can easily take on many foes at once. And his power over water is a huge advantage. He could use water to create distractions or directly attack the villains.
Percy could call upon his friends from Camp Half - Blood to assist him in saving the Padawans. Together, they could form a powerful team against the foes.
Luke in Percy Jackson fanfiction can play various roles. He could be a reformed villain, seeking to make amends for his past actions. This gives a new arc to his character that wasn't fully explored in the original books.
Luke might hold Percy captive to gain some sort of leverage. Maybe he wants to use Percy as a bargaining chip with the gods or Camp Half - Blood. He could be thinking that by having Percy in his hands, he can force the others to give in to his demands.
In fanfiction, Percy could discover some ancient and powerful magic that allows him to create a massive explosion. He might find a magical artifact near the mountain that, when activated, triggers an explosion powerful enough to blow up the whole mountain.