Board Thread:General Discussion/@comment-25247279-20140802061250/@comment-12776-20140804033637

Basically, basically the spirit/demonic energy concept is based on Chinese yin/yang.

For first question, please see Spirit Energy. Female human is yin in yang, they ability to generate spirit energy is extremely weak that it doesn't matter, but they can absorb (and store) it naturally while being in mortal realm (in RPG game, it would mean all girl has SP recovery as default skill, but man gain much more SP from consumable item).

For second, my theory is that there is alway demonic energy link every monster with demon lord. But it obviously doesn't has same attribute as current succubi energy, and most likely not important (I guess it can cause bloodlust instead of lust, but that's it).