In a fanfic, Percy could turn into a dragon as a result of a strange experiment gone wrong. His friends at Camp Half - Blood are initially scared but then realize they need to help him. Percy, in his dragon form, has to deal with his new instincts while also trying to communicate with his friends. They might need to find a way to communicate telepathically. As he gets more used to his form, he could use it to explore parts of the mythical world that were previously inaccessible to him.
One possible plotline could be Percy Jackson finding himself in the 1700s and having to deal with the different forms of mythological creatures that were more prevalent during that time. Maybe he has to stop an ancient evil that was sealed away centuries ago but is now being awakened in the 1700s due to some dark magic rituals.
In this fanfic, it could be that the power of Olympus has become corrupt. Percy, being a hero with a strong sense of justice, decides that the only way to set things right is to destroy it and start anew. He could first target the symbols of the gods' power, like Zeus' lightning bolt. With the help of his friends from Camp Half - Blood, he might stage a full - scale assault on Olympus, using their combined skills and powers to take on the gods and their defenses.
Another plot could involve Percy Jackson being sent to Jack Darby's world. Percy would have to deal with the new technology and different threats there. Maybe he discovers that some of the ancient monsters from his world have a connection to the technology in Jack's world. Jack and Percy would then have to team up to stop these threats from spreading chaos in both their worlds.
One possible plotline could be that Sally is disowned by her family for being involved with the world of the gods. Percy then has to go on a journey to find a way to restore her family's acceptance. He might face various mythological creatures and challenges along the way. Another idea could be that Sally's disownment is part of a plot by an enemy to get to Percy. So Percy has to protect his mother and also figure out who is behind this scheme. It could also be that Sally discovers a dark secret about her family that leads to her being disowned, and Percy helps her uncover the truth and clear her name.
One possible plotline could be that Zuko turns into a dragon to gain a new perspective on his firebending. As a dragon, he might discover ancient firebending techniques that were long forgotten. This could lead him to return to his human form with enhanced skills and a new understanding of his power. He could then use this knowledge to help his friends and bring peace to the Fire Nation.
Perhaps Percy is lost and ends up in the Japanese mythological world. Amaterasu, seeing his unique powers from a different pantheon, decides to help him find his way back. Along the way, they exchange knowledge about their respective mythologies. Percy teaches her about the Greek gods and their quirks, while Amaterasu imparts wisdom about the Japanese spiritual world. This could lead to a mutual respect and a new friendship that bridges the two mythologies.
A plotline could be Percy having to face his own fears and insecurities while being tortured. Maybe he starts to doubt his abilities and heroism. But as the story progresses, he overcomes these doubts through his willpower. Also, the fanfic could explore how the torture affects his relationship with the gods. He might feel betrayed by them for allowing him to end up in Tartarus and this could lead to a change in his loyalty or attitude towards them.
One possible plotline could be Percy gathering a powerful group of demigods and allies. They might embark on a quest to find the ultimate weapon that can defeat Gaea. Along the way, Percy could face many internal struggles, like doubts about his own abilities. He might also have to make some tough choices that could endanger his friends but are necessary to defeat Gaea.
One possible plotline is a quest. They could be on a quest to retrieve a lost weapon that has the power to either save or destroy the world of the gods. Orion could track it using his celestial knowledge, Theseus would be the muscle to fight off any guardians, and Percy would use his connection to the sea to overcome any water - based obstacles.
One possible plotline could be Percy struggling to control Kronos' influence. He might have to fight against Kronos' will to take over his body completely while trying to keep his friends safe.