Lustful essence

Lustful Essence is the polite name of the sexual fluids that demons must consume to fuel and enrich their magic. While the lack of consuming lustful essence does not lead a demon to starve, it does mean their magic will dissipate leaving them no more magical than a common human.

Consuming a very rich variety of lustful essence is the only way a demon is able to reproduce, which generally means that the only new demons that are ever "born" are those born into noble families who are able to amass the most lustful essence.

Lustful essence can be stored near indefinitely in certain enchanted jars, allowing for demons to amass great stockpiles that can last for decades. For example, The Enchantress's palace undercroft sub-level is a storeroom for lustful essence that is enough to last her several lifetimes.

Traditionally, lustful essence is extracted regularly from the demon's thralls. These thralls are formed by overwhelming non-demon sentient species with lust magic, essentially brainwashing them into becoming loyal and perpetually aroused servants ready to be farmed of their essence regularly. However, lustful essence can also be extracted voluntarily without the process of enthrallment, making it possible for other species to simply sell their essence to demons for gold.