Dark Energies

The defining characteristic of the Underhollows, the thing that makes them Underhollows instead of simply underground, is the saturation of so-called 'dark energy'. This energy is a mix of arcane and entropic energy which has a profound, but stable transmutative effect on the material realm. It is called dark energy because it flows downwards, away from the Firmament and the light of the Divine Twins, causing its concentration in the Underhollows.   The transmutative effect of dark energy is responsible for the peculiar nature of the Underhollows, and the traits of its flora, fauna and populace, as well as some of its rarer ores. It is also responsible for a sense of the uncanny which pervades the region, and for an alteration in the tone of all light sources, which inevitably burn more towards the violet.   A common result of this transmutational effect is the deep sight, a form of adaptive dark vision. Deep sight allows a creature to see using part of the dark energy, rather than light, and thus to see in what for surface dwellers would be absolute darkness. With the Colossus War, the dark energy was taunted with ifril, then with rising levels of Necrosis and pure Void energy. As a result, the Underhollows became something of a Soft Place, with only the thinnest layer of Aether and Astra between the material plane, the Grim Plan and The Abyss. This in turn allowed more pollution, and resulted in many creatures of the Underhollows becoming extremely aggressive and destructive.