Just as a large amount of holy power is generated on the emergence of an angel, an inverse amount of unholy power is birthed, manifesting itself in the shape of bizarre entities born from the fears of humanity. Much like a kind of radiation, the unholy power irradiates a region, taking decades until it is fully eliminated. This means that the location an angel receives its blessing becomes a birthing ground for demons, their power and quantity proportional to the weight of the blessing.

  The same way the HL Foundation specializes in the capture of angels, they develop the necessary technology to dispose of demons as efficiently as possible. Unlike angels, these entities can and should be killed on sight.