One possible plot could be that Percy, using his powers over water, manages to control the waters of the Styx in a way that he can manipulate its boundaries. He might use this ability to keep out unwanted creatures or to create a safe passage for his friends. For example, when his comrades need to cross the Styx but are being threatened by the monsters that lurk in its waters, Percy steps in and uses his control to calm the Styx and guide them safely across.
Perhaps Percy discovers that by controlling Styx, he can access some hidden knowledge or power. He could start by accident, like when he's in a battle near the river and his powers react instinctively to the Styx's energy. Then, he has to learn how to use this newfound control without being corrupted by the dark nature of the Styx. He might face challenges from the gods who don't want him to have this power, thinking he'll become too powerful.
In a 'Percy Controls Styx' fanfic, Percy could use his control of the Styx to resurrect a fallen friend. He knows that the Styx has special properties related to life and death. So, he battles the forces of the underworld that oppose his plan. He has to overcome the rules of the Styx which state that resurrection is not allowed. Along the way, he learns more about his own powers and the true nature of the Styx, and also has to deal with the consequences of defying the natural order.
Well, in this fanfiction, Percy controlling the Styx could lead to some really interesting plot developments. Since the Styx has such a significant role in Greek mythology, it could attract all kinds of mythical creatures and gods. Percy could find himself in the middle of a power struggle as different factions either try to use him or stop him. He might also use the Styx to travel to different realms or access hidden knowledge. And perhaps he would have to face the consequences of messing with such a powerful and sacred entity, like facing the wrath of Hades or other underworld deities.
Annabeth could be a main character. She might be skeptical at first about Percy's new ability to control Styx, but then she uses her wisdom to help him understand the implications and possible uses of it. For example, she could research ancient texts to find out if there are any hidden dangers or benefits to Percy's control.
In this fanfiction, Percy Jackson is the central figure as he controls the Styx. But other important characters could be Grover, his satyr friend. Grover has always been there for Percy and could provide support or comical relief. Also, Nico di Angelo could play a significant role. Given his connection to the underworld, he might have some insights or even a conflict with Percy regarding the control of the Styx.
One possibility is that Percy uses his time - controlling ability to prevent a great disaster in his world. Maybe he goes back in time to stop an evil force from being unleashed in the first place.
Well, one possibility could be that Naruto discovers a new power related to silver. Maybe it's a special type of chakra that he can control and it gives him unique abilities like creating silver - based weapons or shields. He could use this new power to defeat powerful enemies or to protect his village in a different way than he usually does.
In this fanfiction, Percy might use his powers and leadership skills to bring order to the camp. Maybe he reorganizes the training schedules, making them more efficient for the demigods to improve their skills.
One possible theme could be the exploration of Annabeth's perspective on Percy's journey in Styx. Maybe it delves into her fears and hopes for him.
A plot could involve Percy's friends being in danger and the only way to save them is by making a deal with the entities in the Styx. He might have to sacrifice something precious, like a part of his powers, in order to gain their help. This would create a great internal conflict for Percy as he weighs the cost of saving his friends against his own abilities.
Another theme could be isolation. Maybe Percy's power to control snow makes him different from others, and he has to deal with feeling alone or misunderstood. For example, if others in his world don't have such powers, they might be afraid of him. This could lead to a theme of self - discovery as Percy tries to figure out his place in the world with this unique ability. Also, a theme of friendship could be present. Percy might find friends who accept him despite his strange power, and they could help him learn to control it better or use it for good.
The Titans could still be a major threat. Even if Lady Styx is involved, the Titans might see an opportunity to use the chaos she causes to their advantage. For example, Kronos could try to ally with Lady Styx to regain his power and overthrow the Olympians once again.