I'd love to see a Game faithful writeup for her.
I have the Dragon write up but that doesn't reflect her actual stats.
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Ravel is a higly irregular hag, as far as her abilities go. If you have access to it, I'd look closely at the Shadow Magic chapter of the Tome of Magic. The magic system revolves around uncovering secrets of shadows and refining their use over time. It seems to suit her
[edit] Reading that over again, this seems familiar. We may have had this discussion already. Might wanna dig around to see if you can find the old one for more ideas