Demons are evil spirits who wish to corrupt and destroy humanity. They have set themselves against God and seek to undermine His creation. They are limited in how they can affect the world, but have two methods which they can use to overcome this. Possession allows them to take control of a corpse, animal, object, or human in order to further their agenda. Pacts allow them to serve a human master in exchange for an increase in power and the chance to corrupt them and cause evil to those around them. Demons are associated with the smell of sulfur (brimstone, traditionally) and are susceptible to particular countermeasures. Their magic usually has an elemental affinity, most commonly to fire.