These are scant notes that will never see the light but I offer them so that someone may redeem them from nihility
Bert the Chimney Sweep/Everyman (his occupation is literally whatever is needed at the time so he always gets a d20 plus 5 on skills rolls)
This suggests a late Victoriana/Edwardian/Georgian or whatever occupations list - I think there was one of these already floating around. Screever, chimney sweep, horse racer, party band, french waiter, suffragette, kite salesman
Steppin time - a vicious dance-off/gang rumble between Mephits and redcaps in the rooftops of a soot-stained hell
D3x2 by d8, then a linear array/repetition of d8. These are all the same height in terms of stories, and the next set can go up (1-2) down (3-4) or stay the same height (5-8) on a d8. Buildings within a block will be relatively close together, but there may be alleys and parks and long perilous drops back to material reality. You can get sucked up to the Chimney sweep World anytime you investigate chimneys which are literal liminal zones between the prime and the smoke-lands
Related to: Margaret St. Clair's linear dungeon crawl which I never finished because in retrospect the hero of that Shadow People book had a tough slog of it and the principle was sound in terms of mechanics and simulation but maybe UN-fun overall
Smoke Form Spell - not for people but for using smoke to make semi-material objects. See the soot-city of Haon and Ylill in the Purple Planet boxed set. I still haven't played this chunk of the thing out despite my quantum-ogre-ing trying to kidnap, cajole, and seduce the PP party into it...
Smoke Mephits made from ashes and soot. Triple damage from wind and from brushes but nothing else affects them in the slightest. Unflappable and maliciously cheery.
Efreet Prince of Smoke like Yan C'Bin or that other one. A boss monster. Nattily dressed and imperious. Maybe a tophat
Mary has many wiles: charm, suggestion, levitation, animation of objects, extra-dimensional spaces, and planar step into pseudo-realities. She can speak to animals and see the future. BY GUM SHE IS A WITCH