@FatPrincess Hello and welcome! I like the character idea, just a few things to hash out:
How familiar would you say you are with the series? As an inhabitant of the Witches' Forest, it's very likely she'd never have encountered men, at least not directly, until entering the Clover Kingdom. The Witches are kind of an autonomous group, all-female, and many of them possess types of magic that are considered taboo or unsavory by other kingdoms. They've also had conflict with both Clover and Diamond Kingdoms in the past, so there are some negative feelings on all sides. I feel like this might need to play more into her personality or fears somehow, although feeling superior to non-Witches is a good start. What are your thoughts?
For the prophecy mentioned in the backstory, if it's a major element you'd prefer to keep secret, that's something we'd probably need to figure out over PM. Otherwise, did you have any specific plans for it?
For her labyrinth spell in particular, due to the nature of Mist Magic even if the walls are magically "solidified," it's not really going to be the same as something like earth magic or stone. It matches the themes of illusion and misdirection used with that magic type in the series pretty well, but in canon Mist Magic is also presented as fairly easy to scatter, especially with Wind magic. The ability of the labyrinth to recover would offset this, but I just thought I'd point it out--certain types of enemies would likely only be slowed down by it, and more powerful foes might just tear right through it.