Perhaps Mist Essence could have a drug power on it, as it's supposed to be an intoxicant?
It gives -10 Will, that's pretty intoxicating :)
Mist Junkies ftw
i agree
You can use it as an RPed drug by firing it at your PCs feet, but that requires an open space free of NPCs that'll kill you for getting them high ;). I was thinking the power could do something like giving you -10 Mind saves, Spell Focus Divination, to make it attractive for seer/visionary PCs of any class to use.
It could have both the mind for, single use propiety and what you describe, you can choose how to use it. Adiction to it would be pretty harsh though, considering how dificult it would be to get, so the benefits better be very nice!
The mist isn't a drug though?