All scents supernatural species carry are not at all able to be smelled by humans, even on their best day, but their fellows on the other hand use scent as half the distinction between who’s who.
Demons carry an odd scent, depending on the demon it can be a perfume of pure temptation, of danger and one of the most enticing things to the mind. For some demons, it smells more along the lines of the pits of hell, though most reapers believe them to smell this way regardless.
Angels typically have an almost perfume like scent, almost as if they bathed in the most calming of herbal remedies. Unlike any other species, their scent can at times be detected by humans they are trying to comfort or collaborate with. Their odor is supposed to serve the purpose of calming, though some call it the scent of pointless brain washing to weak subjects.
Reapers usually smell like death, soil, and generally the smell of freshly deceased. Though unlike the thick scent of their fellows, their own is far more subtle and harder to detect than others.