There are technicaly two types of demons. The first one is the original demons that came from hell itself, like the succubi, demoenttes, lesser demons, greater demons, etc etc. The other type is the demon spawn, or demon like creatures made by the demons that got through, to aid them in killing/****ing everything. The actual demons have the powers like throwing pure demonic energy at you, corrupting you, etc etc. The demon spawn have a demonic fear aura, and evolve really fast, and are infectious.