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.
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.
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.
In a 'Percy son of Hades fanfiction', there are many characters that could be added. For example, Charon, the ferryman of the Underworld. He could play a role in Percy's travels within the Underworld. Persephone could also be an important character. She might be initially suspicious of Percy but then come to see his potential. Additionally, the Erinyes, or the Furies as they are more commonly known, could be added. They could be a source of conflict or assistance for Percy, depending on the situation.
A vampire scientist. This character could be researching ways to create a new type of vampire that is immune to the weaknesses of traditional vampires, like sunlight or silver. Their experiments could cause a stir among both the vampire and lycan communities.
One potential character could be a new sidekick for Batgirl Beyond. Maybe a young girl who idolizes Batgirl and has some unique skills like acrobatics or martial arts training. She could bring a fresh dynamic to the story and help Batgirl in her missions.
One potential character is a young wizard named Merlin Jr. He's still learning his magic but is always eager to show off to Luna. There could also be a group of forest sprites. They're mischievous but friendly, and they often play pranks on Luna which she takes in good humor. Additionally, a gentle giant named Giganto who lives on the outskirts of the kingdom. He helps Luna when she needs to move big things, like a fallen tree that's blocking a path in the forest.
One potential character could be a rogue alien scientist who is interested in Big Chill's biology. Another could be a young alien apprentice who looks up to Big Chill. And a third could be an ancient alien guardian who has knowledge about Big Chill's species' history.
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.