Negative Energy Plane
Within the Inner Planar Region, and of an opposing nature to that of the Positive Energy Plane, the Negative Energy Plane exists. This is a plane of dread, a realm of extreme darkness and death. It's a largely featureless and empty plane, lacking even air, representing the epitome of darkness where all life is extinguished. This plane poses a constant threat to life, as it draws in and consumes living energy. Mortal and immortal beings alike rapidly decay in this environment, leading to an agonizing demise. Survival here is almost impossible without magical protection, because of its life draining, lethal and decaying nature.
Travelers to the Negative Energy Plane face two immediate dangers. First, the absence of air presents a significant challenge to breathing and survival. Secondly, there's a continual drain of life energy experienced by anyone who enters this plane. This relentless energy drain leads to rapid decay and eventual death, making this plane extremely perilous for both mortal and even immortal beings. Even light is fundamentally altered. Any non-magical light source is immediately extinguished in this realm, and even magical light cannot sustain itself for long, dimming quickly under the plane's oppressive nature.
There are few natural features in the endless void of this plane. Landmasses present are brought from other planes, but these too succumb to decay over time. Constructions on these landmasses deteriorate rapidly. Sometimes the darkness condense enough to become solid. This kind of material is called voidstone, and is extremely hazardous; anything that touches these solid blocks of absolute darkness is destroyed swiftly.
Despite its harsh conditions, is not devoid of inhabitants. Sentient undead have made this plane their home, particularly in areas where the negative energy is less intense. The only native inhabitants of this plane are the Nihilorion, a unique species that thrives in this extreme environment.