Definitely include Percy and Annabeth. They are the central characters in the original series and their relationship and skills are key. Percy with his water - related powers and Annabeth with her wisdom and strategic thinking.
One popular original character is a new demigod named Lyra. She has the power to control the elements of air and is often depicted as a fierce fighter. Another is a centaur named Orion who is a bit of a rebel. He doesn't follow the traditional centaur ways and often helps the demigods in unexpected ways. And then there's a nymph called Iris who has the ability to create illusions and is a bit of a trickster, which makes her really interesting in the fanfiction world.
Percy Jackson is one of the main characters. Annabeth Chase is also very important as the story likely has a lot to do with the Mark of Athena which is related to her. There are probably other characters like Grover who are also part of Percy's group of friends.
Grover could be an interesting addition. Even though he's a satyr, his loyalty to Percy and his own unique skills could be put to good use in a sea - centered story. Maybe Nereids, the sea nymphs. They can bring an element of mystery and beauty to the fanfiction and might be able to help Percy in some way. Another option is Chiron, who could guide Percy from the shore in his sea - related quests.
One interesting plot twist could be that Annabeth discovers a hidden power within herself that has nothing to do with Athena. Maybe she can suddenly communicate with mythical creatures in a way no one else can. Another could be Percy finding out that he has a long - lost sibling who is actually on the side of the enemy, but then later switches sides. And a third one might be that the Mark of Athena is actually a fake, created by an enemy to mislead the demigods and lead them into a trap.
One idea could be a new quest where Percy and Annabeth have to find a lost artifact related to Athena that was stolen by a rogue demigod. This would involve them traveling to new and dangerous places, facing off against mythical creatures they haven't encountered before.
The gods themselves could be interesting characters to include. For example, Poseidon could offer Percy more power or advice at crucial moments. Athena could also play a role, perhaps initially being an adversary because of her different goals, but later becoming an ally. Even minor gods like Hecate could be included. Her magic could be used to help Percy in situations where his normal powers aren't enough. Also, new characters created specifically for the fanfiction, like a powerful demigod from a previously unheard - of lineage, could add an element of surprise and freshness to the story.
Annabeth Chase would be a great character to include. She is smart and can help Percy with strategizing in difficult situations. Her knowledge of architecture and ancient history can come in handy when they are exploring new places in the ocean world.
Annabeth would be a great character to include. She could use her intelligence to help Percy solve problems and strategize against their enemies in the underwater world.
It's about the adventures of Percy Jackson. In this graphic novel, there are likely more visual interpretations of the story elements. It probably involves Percy and his friends facing various challenges related to the Mark of Athena, which is an important element in the Percy Jackson series.
Annabeth is also often a prominent character in such fanfictions. As a daughter of Athena, she can act as a bridge between Percy and Athena. Her own skills and relationship with Percy add depth to the stories.