Hopefully, it's still considered fandom-related to want to use canon sources but play with original characters. I would love to bring some people together and brainstorm an original world saving teen group with an emphasis on friendship, lore, and worldbuilding. Some fandoms that immediately come to mind include Sailor Moon, Power Rangers, Captain Planet, Avatar: The Last Airbender, and Space Cases. Typically, I'm willing to pick up multiple characters of both genders to help fill out the world and drive the storyline. Similarly minded partners would be fantastic!
Another fandom idea I wouldn't mind playing with is Stardew Valley (obviously). Small town setting but with magical elements. Our characters could explore monster-infested mines for valuable materials and have to actively combat a greedy corporation from buying out the majority of their hometown. The bottom line is that I want a setting that isn't strictly slice-of-life. The more unusual opportunities, the better.