Generally a creature created by Alchemy, Hachnar's Homunculii are greatly unusual. They are much larger, 3' in height and are generally thought by those who see them to be some form of gnome or mutant dwarf.
They were derived from materials provided by Hachnar as well as several different animals. They have a fraction of his magical ability and share a telepathic link with Hachnar. Hachnar can see and hear through them them by concentration, limited to about 20 miles radius. Hachnar can also channel spells through them if necessary.
If slain, a powerful magical backlash will occur, moderately injuring Hachnar. Go to Comment
I had touched a little bit on the outgassing in the Main Lab section - the ventalation is the most Magic heavy aspect of the location. Since having toxic gas clouds appear in the middle of a city can bring undue attention to one's facilitity, magic can be used to send the clouds elsewhere.
A secret dumbwaiter between the two buildings is a good idea - and another above-ground front to sell the illegal wares is also good. I was focusing on secrecy above all, but I'll adjust the sub with your ideas in mind. The underground lab will stay, but a secondary location (containing the Parlor) will be added.
On sentance needs to be chopped up a little or restructured:
The sound cannot be located simply because it is an illusion and is entirely in the person's head, part of the mild insanity caused by such an unnerving sound can cause the target to think he has an idea as to the direction of the sound only to prove him incorrect (which can be unnerving).
Recognizing the threat that cigars present to sentries everywhere - giving away their position when lit, ruining nightvision by their flare, and signaling others by their smell.
These special stogies are enchanted to provide to the user the illusion of smell, and light, but in reality the effects are not perceived by those not smoking them. They are ignited simply by puffing on them but again no flare is visible to anyone except the user.
They are still burning, but very dimly. They do radiate heat which may still give the user away. Go to Comment