One possible plot twist could be that Artemis's blindfold is actually a self - imposed thing to gain a new power, and Percy discovers this secret halfway through the story. This would completely change their dynamic as Percy realizes he may not have been needed as much as he thought.
One common plot twist could be Percy discovering that his connection to Artemis brings some unforeseen powers. For example, he might gain the ability to communicate with certain animals that are sacred to Artemis. Another could be that there's a prophecy about him that was hidden until a crucial moment, changing the course of his journey. Or perhaps he finds out that his parentage is more complex than he thought, with some dark secret related to Artemis that others have been hiding.
One possible plot twist could be that Triton is not actually there to help Percy but is being controlled by an enemy to spy on him. So, Percy might think he has a new ally but in fact, he is being set up.
One potential plot twist could be that the gods try to keep his true parentage a secret, but Percy discovers it through a series of strange dreams or visions. Another could be that he has a power that is completely unexpected, like the ability to combine the powers of the moon (from Artemis) and the sea (from Poseidon) in a way that no one has ever seen before. For example, he could create tidal waves that are influenced by the phases of the moon.
The element of vulnerability is also quite prominent. Percy, who is usually a very capable hero, becomes more vulnerable when blindfolded. This makes the reader more empathetic towards him and also creates more opportunities for character development. For example, he might learn to be more patient or more in tune with his instincts while in this vulnerable state.
A great plot twist could be that Percy, as the champion of Artemis, has to deal with the jealousy of other gods. Since Artemis is a powerful and respected goddess, some other gods might not be happy about Percy being her champion. This could lead to various challenges for Percy, such as being framed for a crime he didn't commit by a jealous god. Or perhaps, there could be a twist where the hunters of Artemis have mixed feelings about Percy. Some might see him as an intruder, while others start to develop a different kind of respect for him, which creates internal conflicts within the group of hunters.
There's also a fanfic where Percy is blindfolded during a capture - the - flag game. In this one, he has to rely on his other senses and his friends' guidance more than ever. It really shows how much he's grown in his abilities. This fanfic is great for those who like to see the characters pushed out of their comfort zones.
One idea could be Percy having to team up with Artemis to rescue some captured demigods. They could face off against a new and powerful monster in the process.
One possible plot could be that Percy comes across a disabled Artemis in a situation where she has lost some of her powers. He could help her find a way to regain them while facing various mythological threats. For example, they might have to battle a new kind of monster that is taking advantage of Artemis's weakened state. Along the way, Percy discovers more about the true nature of the gods and their vulnerabilities.
In this fanfic, the story might involve Percy having to go on a quest to find a special ingredient to heal Artemis. Along the way, he faces various challenges and overcomes them with his wits and the help of his friends. When he finally gets the ingredient, he uses it in a ritual that combines his demigod powers with some ancient magic to heal Artemis.
One possible plot twist could be that she discovers she has a different parentage than she thought. Maybe Hades isn't really her father, but someone else who had a reason to leave her with Hades. Another twist could be that she has to fight against Hades at some point, even though he raised her.