The demons that swept across the face of the earth when the gates of Hell opened are varied in size, shape, ability and power. The careful observer will note that these abominations fall into one of four distinct categories, or castes.
Beasts are the lower forms of life in Hell. They are the naturally occurring fauna of the Underworld, made evil by their surroundings and their masters. True Demons see them as fodder to subjugate, abuse, brand, armor and train for battle. Beasts are unintelligent and commonly oriented towards melee combat, attacking with fangs and claws. While susceptible to most types of damage, Beasts of greater power and age can be extremely large and strong, a few reportedly towering over city buildings. Some of these creatures also employ attacks representative of their infernal origins, unleashing corrosive, poisonous or fiery effects on their unlucky targets. In terms of natural defenses, the more brutish varieties have thick, armored hides while their smaller, wiry kin rely on their agility to avoid attacks.
Though not truly undead, most Necro's are still living humans that encountered souleating spectral demons. What's left of the person is a body with a few shreds of soul, enough to keep it alive, but in mindless and eternal agony over the loss. In their search for anything that will fill the void in them, they seek out the healthy living, trying to capture a soul to ease their pain. The mindless ones have gotten many poor victims, but too little avail as they lack any capability to drain souls themselves. Whenever an undead catches a victim, the spectrals will find plenty of food.
This caste includes both the undead and the demons that create and command them. Necros often swarm in semi-organized packs, using strength of numbers to overcome the limitations of their commonly weakened and decayed forms. Although usually simple to knock down, some may rise again unless appropriate measures are taken. Their masters are more powerful, and eliminating their commanding presence should be of the highest priority when encountering them. Creatures within the Necros caste commonly use attacks that pierce the flesh, poison the blood and corrupt the soul. It is important to note that they are particularly resistant to these same sorts of attacks.
These are semi-corporeal beings with powerful magical abilities at their disposal. They exist, at least partially, on an alternate and parallel realm of existence known as the Spectral plane, making them difficult to fight using normal physical means. Spectral demons are visually the strangest and most shocking creatures encountered by the survivors of the Burn, and some even have hidden forms that can only be seen by adventurers with a means to peer into their unearthly realm. Their Spectral power sometimes manifests itself in our world as a form of electricity, and attacks based in similar energy spectrums have been found to be highly effective.
Also called True Demons, or Primus, these are the organized beings that command the lesser castes and are the primary cause of the apocalypse. Mostly humanoid in form, they often use weapons and equipment in their vile pursuits, and some have even been seen using human-created technology, although they tend to favor devices of their own fabrication. Their intelligence, use of weaponry, and the ability to attack from both range or in hand-to-hand combat make them a dangerous and unpredictable enemy. Demons also wear armor that is commonly resistant to traditionally infernal types of damage, such as fire and employ mystic shields to safeguard them against more temporal forms of damage.