Mamono Mana

Demonic energy, often abbreviated DE and alternatively translated as monster's mana, is a kind of "life force" which is possessed by monsters in the Monster Girl Encyclopedia world. The yin-yang analogue of the spirit energy which is possessed by humans and other mortal creatures, demonic energy sustains monsters in a basic, metaphysical sense, as well as powering their magical abilities. It has several powers that spirit energy does not; most obviously its ability to corrupt creatures, environments, and even gods into demonic perversions. However, its disadvantage is that demonic beings do not generate this energy within themselves like spirit beings do. Instead, they must consume spirit energy in order to convert it into demonic energy. This is one of the reasons that monstergirls hunger insatiably for semen: it contains more spirit energy than anything else, so constitutes a feast for their demon constitutions.

When highly concentrated, demonic energy can appear as a physical substance: a black, tarry goo that spontaneously forms into ominous, tendril-trailing spheres. Too much in one place may spawn its own elemental, a dark matter.

General features
Technically each species of monster has its own demonic energy: so there's werewolf demonic energy; bubble slime demonic energy; vampire demonic energy, etc. In the age of the former Demon Lord, these energies remained with their respective species, but the current Demon Lord has forced her own succubus demonic energy into every species. This is why the monsters are now monstergirls, with curvy female bodies, sky-high lusts, and the ability (or requirement) to use semen as a dietary staple. It's also why getting bitten by a large mouse turns female victims into the same monster: when enough of the relevant type of demonic energy enters her body, a woman transforms according to the specific source of her magical corruption.

As well as powering monsters' basic existence in general, demonic energy in surplus strengthens their spells, boosts their physical abilities, ramps up their lusts, and lengthens their lifespans. Different monster species innately have different amounts of this energy, which is what accounts for the power difference between, for example, slimes and lilims. Nevertheless, all monsters from slimes to lilims can massively boost their powers by amassing more demonic energy; and the way to do this is to have more sex and take in more spirit energy. As with humans and elves and dwarves, monsters' exertion, spell-casting, and just generally being alive causes demonic energy to be lost from their bodies. Although they can survive on "starvation rations" with the spirit energy contained in normal foods, this is both unpleasant and unhealthy in the long term.

In spite of the monstergirl's general hedonism and indolence, demonic energy spellcasting seems to be one field where monsters are better developed and researched than their human nemeses. The initial remit - and, indeed, the official name - of the Sabbath HQ is the "Demon Lord's Army: Spell Casting Unit", and despite veering the organization at right angles to become a loli supremacist religion, the baphomets continue R&D of demonic energy spells. Individual liches often take up demonic spell research too.

Passive effects
The passive effects of demonic energy are possibly more important than the active, hex-throwing ones: it transforms human lands into ominous demon realms, and then induces mana corruption in females who enter them. On a more personal level, the part-succubus nature of the energy causes mental, physical, and metaphysical aspects to turn towards sex. Infirmities heal, moods turn lustful, and a crazed ushi-oni with knives for feet and a grip that crushes boulders can savagely rape a petite shota for days on end without anyone dying.

Demonic energy is partly empathic in its effects. For married monster-incubus couples, the magical effect subtly molds the bodies of both towards their opposite number's preferred sex-fantasy: most obviously, incubi changing their age-appearance to match their mate's taste. To an extent, demonic energy is also shaped by the Demon Lord; monsters' usual preference for monogamy, and not stealing other monster's husbands, is attributed to some of her personality traits being transmitted to her subordinates via demonic energy.

Book Information

 * There are very many sections in the various Monster Girl Encyclopedias that cover demonic energy. In addition to the texts below, see also The Source of Demonic Energy, The Various Roles of Demonic Energy, Succubus' Demonic Energy, Mana Corruption