This is a feat from Blood of the Night, and it's confusing. Here's the full text:
Improved Gaseous FormYour gaseous state is more potent than that of your peers.
Benefit: As a standard action, you can assume gaseous form at will (caster level 5th), but can remain gaseous
indefinitely and have a fly speed of 20 feet with perfect maneuverability. This is a supernatural ability.
If you already possess the gaseous form special quality, you can instead choose to augment your gaseous form in
one of the following ways. These effects apply only to creatures that enter your space while you are in gaseous form.
Glitterdust (Su): Creatures must succeed at a Will save or be blinded and outlined in golden particles as
though under the effects of glitterdust.
Mind Fog (Su): Creatures must succeed at a Will save or take penalties as though under the effects of mind fog.
This effect lasts as long as a creature shares your space and for 2d6 rounds after.
Special: You can gain this feat multiple times. Each time you take this feat, choose another swarm type.
Questions questions, so many questions.
1) Suppose a standard vampire who already has gaseous form takes this feat. Must she make a choice between Glitterdust and Mind Fog once, when the feat is taken, or each time she assumes gaseous form?
The "Special" line about taking the feat multiple times would suggest that you choose one when you take the feat, but then it goes on to talk about choosing a swarm type. That's clearly a copy-paste error from the "Improved Swarm Form" feat on the same page, but since it doesn't actually say you have to pick one manifestation when you take the feat, it's totally ambiguous.
2) Suppose we have a face-off between Vina Vampire and Perry Paladin. They are standing directly adjacent to one another, thus:
As a standard action, Vina goes gaseous. She has Improved Gaseous Form, and has chosen Mind Fog. The feat says that the Glitterdust/Mind Fog effects "apply only to creatures that enter your space while you are in gaseous form." Does this mean:
2A) That Perry has to voluntarily step into Vina's square? Or,
2B) Can Vina step into Perry's square to force a Will save against Mind Fog?
3) Assuming the answer to 2B is "yes, she can step into his square to force the save", how often can she force that save? The options are:
- every time she enters his square
- once per round when she enters his square
- once per some longer interval (minute/day/month)
- once per time she assumes gaseous form, because it counts as a separate casting of "Mind Fog"
If it's EVERY time she enters his square, she has 20 feet of movement, and can therefore force Perry to make 2 saves against Mind Fog in the same round that she became gaseous with a simple move action (in, save, out, in, save, out). If she can manage a double-move or a run using the same trick, that's a whole lot more saves.
Anyway, sooner or later, Perry is going to fail that Will save, and incur a -10 penalty on Will saves for AT LEAST 2 rounds -- plenty of time for Vina to curdle his brains with Dominate Person, and order him to murder his colleagues.
4) This is actually unrelated to the feat specifically, but can a creature in gaseous form fly into an opponent's lungs and just sit in there, thereby triggering the suffocation rules? Because that would be positively evil.