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.
A character like a magical talking rabbit named Thumper could be added. He can hop really fast and takes Luna to secret places in the meadows. A fairy godmother - like figure named Glinda could also be there. She gives Luna little gifts and helps her when she's in trouble. And don't forget a little elf named Tinker. He's really good at making things and he helps Luna create little trinkets for her friends in the fanfic.
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 young Martian inventor could be a great addition. This character could create unique gadgets and machines that help the protagonists in their adventures. For example, a flying device that can travel at high speeds across Mars.
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 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 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 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.
A detective who is investigating the strange disappearances in the building where Rosemary lives. He could be skeptical at first but then start to believe Rosemary's story as he uncovers more evidence.
A nomadic vampire with a completely different set of values compared to the Cullens. He could be more in tune with his animalistic side and not believe in the Cullens' way of trying to blend in with humans. His presence could cause conflict within the vampire community in Forks and also attract the attention of the werewolves.
One possibility is a young girl who has the ability to control light in a way different from Ruby's speed. She could be a street urchin who has been surviving on her own in the slums of a major city in Remnant. When she meets the RWBY team, she initially distrusts them but eventually becomes an important part of their group. Also, a grizzled old veteran of many battles against Grimm could be added. He could be a mentor figure, teaching the RWBY characters new combat techniques and sharing his wisdom about the history of Remnant and the Grimm.
There could also be a group of street - smart kids who befriend the Baudelaires. They have their own set of skills and stories, and together they can form a sort of alliance to protect their neighborhood from any potential threats. These new characters would bring in fresh perspectives and interactions for the existing characters in the fanfic.