An old and forgotten god who has a grudge against Artemis and sees Percy as a way to get to her. This god could be a powerful antagonist, adding a new layer of conflict to the fanfic. His powers could be something that neither Percy nor Artemis have faced before, forcing them to quickly adapt and find new ways to defend themselves and fight back.
A centaur who has knowledge of ancient prophecies involving both Percy and Artemis could be added. The centaur could act as a guide or a mentor to them during their adventure. He could provide crucial information about the enemies they are facing and how to use their combined powers effectively. For example, he might know of a weakness in a powerful foe that only Percy's unique abilities and Artemis' lunar powers can exploit.
One potential character could be a wise old hermit who lives in a secluded part of the paradise. He could offer Percy valuable advice and knowledge about the secrets of the paradise.
Another great addition could be Circe. She has a lot of knowledge about magic and the supernatural. In the fanfiction, she could be an ally or an enemy. If she's an ally, she could teach Percy and Artemis some spells to combat the chaos - influenced threats. If she's an enemy, she could be working with the forces of chaos to try and gain more power.
A new healer character could be added. This character could be both intrigued and a bit wary of Percy's blood - bending ability and could try to help him understand it better.
A shape - shifting creature that can take on the form of any animal. It starts off as an enemy, trying to steal something important from Percy and the Wanderer, but later realizes they are on the same side and becomes an ally. This character could bring a lot of action and mystery to the fanfiction.
A new character could be a mortal who has somehow gained the ability to see through the Mist completely. This mortal is on a mission to expose the world of demigods and the gods themselves. Percy has to either convince this mortal to keep quiet or find a way to make them forget what they've seen, all while dealing with the chaos this person is causing in the demigod world.
A Venator wizard who can manipulate time could be an interesting addition. He could help Percy in his quests by using his time - manipulation powers to gain an advantage. Another could be a half - Venator, half - demigod character who is conflicted about which world to side with.
A new type of sea nymph who has the ability to change the color and texture of water. She could be from a far - off part of the ocean that Percy has never explored. Her appearance could bring new mysteries and adventures for Percy, as she might know secrets about the deep sea that are crucial to the safety of the demigod world.
You could add a new demigod character. Maybe a child of Hecate who can use magic in interesting ways around the school. For example, she could make the lockers disappear or change the school cafeteria into a magical forest for a short time. Another character could be a satyr who is pretending to be a normal student but is really there to protect the demigod students. He could be the one who always seems to be eating strange things from his backpack, like enchanted herbs.
A young demigod who has the power to communicate with the spirits of the monsters. This character could help Percy understand the motives of the monsters better and maybe find non - violent solutions to some of the conflicts.
Grover Underwood could be included. His knowledge of nature and his ability to sense danger could be very useful. He could provide some comical relief in the midst of the serious prophecy - related events. And his loyalty to Percy would ensure that he is always there to support him, even when dealing with the often - prickly Artemis.