This is off-topic from the new books, but I've got a villain to design. (Ars Baltica players, begone.)
In our new saga, the PC magi will arrive at an isolated winter covenant that has invited them to help revive its lagging fortunes. This winter covenant has only two magi left, an extraordinarily famous Verditius archmagus (about whom more questions another time), and someone else, probably an Ex Misc. The extraordinarily famous Verditius has, through some sort of diabolic behavior, repaired his Gift, and has the spell-casting abilities of an ordinary Hermetic magus. The diabolic behavior hasn't stopped, and the Ex Misc has gotten wind of the black rites in the forge.
Here's what I want. I want the Verditius to magic the Ex Misc to keep her from hindering his plans. But I want the Ex Misc to retain enough autonomy that she, under false pretenses, invited the PC magi to join the covenant, hoping that they'll find out what the Verdi is up to in time to stop his diabolical scheming.
So, my question is, what would the Verdi have tried to do to control her? And how might it have gone wrong so that the Ex Misc retains some secret autonomy, and can subtly get around the mental blocks the Verdi has produced?
I was thinking that he might have put some item (e.g., necklace) with a powerful ReMe effect on her, the effect being to make her powerless to act against him. It's powerful and has high penetration because of the Vis Sordida the Verdi used to make the item, but, for the same reason, it's prone to sneakily betray its creator and let the Ex Misc do things she wasn't supposed to be able to do.
An alternative would be that the Verdi is continually scrying on the Ex Misc, and so she just has to make plausible excuses lest he boil her for her vis. (Code? What Code? They're in a swamp in now-Latvia. They haven't had a Redcap in twenty years, or an Inquisitor in fifty.)