Those last couple of posts bumped this thread up above my radar for a while. Where are we on this critter?
Well I've finished work...
Updating Ash Quasi-Elemental.
Updating Dust Quasi-Elemental.
Updating Vacuum Quasi-Elemental.
I agree. This reads more like a continuous aura than a transformation. So maybe any time a vacuum quasi is in an atmosphere, it has the void storm around it.
I don't see where they have to turn it on. And the 10 round max only applies in "regions of abundant air" although the void storm still sucks breath even in airless areas like Vacuum. It's a weird ability.
Well, assuming the PCs have magic to travel to the quasielemental plane of vacuum, it should function all the time. But your point is fair enough. Maybe something like
Void Storm (Su): A vacuum quasi-elemental can suck all air within the listed diameter into itself. This process creates a wind of strength listed and deals the listed damage to all breathing creatures in the void storm as air is ripped from them. In regions of mostly vacuum, there is no limit to this ability, but a vacuum quasi-elemental can only use this ability for 10 rounds/day in regions of abundant air such as the Prime Material Plane.
There's no restriction against its use in Vacuum in the 1E version, and I'd say it's necessary for it to "to reduce any area of confinement to the the same level of airlessness as their native plane." On the other hand, the mechanics I wrote don't specify one way or the other, and I'm not married to either interpretation.