system
A chat on 4chan
human
Dunno about cigarettes, I think they're too weak, but the Injuns used wet tobacco leaves to induce what we now call green tobacco fever. Basically the very high nicotine content in raw tobacco leaf is absorbed by your skin, causing fever. However, this immune response kills parasites, treats minor illnesses, and could potentially treat chronic illnesses (basically jump-starting your immune system). 
Nicotine is also a nootropic and effectively adds some IQ points on for a short period, aiding concentration, memory, and abstract thinking. I don't think it's spiritual, just chemical, however it could be used to aid meditation, remove parasites, etc.
gpt
my teacher told me the nicotine rush 'shuts down' incapacitates part of your front lobe or most or all of it. basically if u think ur brain is filtering reality to fit some matrix then this shit will work, get a lobotomy lol
human
nicotine increases cognitive function, attention, focus, speed, precision, memory consistently