Probably, considering we've implemented acid shields that spill on opponents. As for how exactly I wouldn't know, my C knowledge is still lacking.

Oh! Now that you mention it I do vaguely remember that quest though similarly I can't remember what it did.
Time to go check so I can update the wiki I guess.

EDIT: Ok, that was easy enough. Completing the quest for the witch (priestess of Scabies) grants you the map to the Tomb of Xinroch, which is currently unfinished. Time to go update the wiki, thanks Zayre for bringing this up.

On a related and amusing note, the only other things with a gas immunity tag and functioning noses are orcs and skunks.
I believe that is because they are used to naturally smelling like satan's rotting bumhole.

In fact all the top tier monsters refuse to step foot in fart clouds including Elpuri, Oree, Petrus and Ischaldirh (not that he needs to move).

I do believe this means that every single breathing monster in IVAN is afraid of farts. (Or rather everything that doesn't have a GAS_IMMUNITY tag. That's most of the named dudes.)

Just tested it, and yes fart gas will immobilize Sherry and block her passage.

Ooh, that's something to look into. I think they'd be able to attack you if they're in an adjacent tile, and this is a little bit more plausible in vanilla IVAN where you're unlikely to have more than 1 fart cloud tile to stand in.
I'll test it later today if someone doesn't beat me to it.

Demonhead I would be willing to believe is just because it sounds cool for a super-big axe.
But a gaseous sword that creates wind vortexes? I feel there has to be a basis for it somewhere.

Well yeah, I've been working off the script files and booting up LIVAN to check. I guess I should also grab LIVAN's source to dig through at some point.

I've made some additions to the wiki on what I've found - for example Defender which I initially thought had no special properties to speak of has a much higher roundness meaning that it is much better at blocking than a standard knight sword and thus fits its name.
The other "no ability" weapons are similar and are more or less direct upgrades from their standard counterparts - generally higher strength/form modifiers and roundness as well as additional material volume.

Let it be known that lanterns actually make really good weapons.
They have a blocking modifier greater than most weapons, only being outclassed by battle-axes and halberds in vanilla IVAN (also rapiers, tip swords, great axes and spetums in (C)LIVAN).

In addition they actually do decent damage to begin with which will only get better as your skill/accustomization increases.
Being made of glass they also upgrade directly to Illithium which you can do the moment you find a SoHM and reach 25 INT which largely mitigates their greatest weakness - being fragile.
Speaking of being fragile, that hardly matters because of the sheer number of lanterns you can simply run and pull off the wall to club people with.

Their biggest downfall is that they cannot be enchanted by any means so far as I can see, and normal glass lanterns started to be lacking in damage come Jenny, but Illithium ones are much stronger.

Thanks a bunch, Pent.
So I guess the unobvious weapons really are just stronger versions of regular weapons after all.

Also going to need a bit of a consensus on what the Vacuum Blade is a reference to.
It's a gaseous sword that does minimal damage (0-1), but has a chance to proc a powerful "wind vortex" for massive damage. It also emits an orange light for some reason.
Here's what I've got:

• The Vorpal Sword from the Jabberwocky poem.
  
• An old trope in manga/anime/movies of breathing chi onto a blade to enhance its sharpness or allow it to fire off air beam blades when swung. Except without the already-present-blade part.