Demon

The term Demon refers to a family of artificial soul types. Although the exact characteristics of a Demon vary on their subspecies, there are always three constants: They are created via the use of Axiom, must consume souls and/or energy for sustenance, and are able to kill Devils.

Demons are sometimes referred to as artificial Devils, due to the fact they were discovered during an attempt to create another Devil. The process of creating The Judge is believed to have been similar to the creation process of Demons.

They are specifically tailored to kill Devils, via cutting off the Axiom supply their spark has to the Devil pool. Demons in particular function by intercepting the connection Devils have with the Orgin Axiom Pool, which does cause venomization. Although Demons can kill other spark based entities, it is more difficult for them to do so because their axiom connection is not as intuitive to them. Unless, of course, said entities are also connected to the Orgin Axiom Pool, which is rather unlikely.

Venomization
Whenever a Demon kills a Devil or absorbs their power, venomization occurs. This results in a Demon not only becoming stronger, but also becoming more violent. It is a result of them feeding off of the Axiom energy. Their souls automatically react by using up the energy, in order to not overload them; Soul energy and Axiom do not mix well.

It is widely believed that when demons consume souls, they venomize as well. However, this is to a much lesser degree than with Axiom energy and provides less drastic results. This would also explain how Demons sometimes become addicted to eating souls, and consume far more than their hunger requirements call for.

Venomization is one of the most dangerous things about Demons, as it can result in a snowball of death and destruction. Most Devil kills Demon have are multikills due to it. That is why so many entities throughout the multiverse want to eliminate Demons as soon as possible, before venomization occurs and causes a snowball of destruction.

Views on Demons in the Multiverse
Devils have an almost irrational phobia of Demons, due to the fact they are one of the few things in the multiverse that can kill them. Because of this, it is illegal for a Devil to create a Demon. Even those who are not bound by the contracts who attempt to create a Demon typically find themselves quickly hunted down by both contract and outlaw devils alike.

Devils aren't the only entities that fear Demons, however. Due to their need to consume souls, Demons typically end up as mass murderers that end countless lives. Because of their power and general difficultly to kill, a Demon can sweep clean multiple planets easily, as the general inhabitant of 3D is defensiveness towards them.

In order to protect Devils from Demons, The Judge have created the descriptive Demon Killing Squad in order to eliminate any that are discovered. The DKS itself consists mostly of Demons itself, as it just so happens Demons excel at killing their brethren. They either eliminate demons by killing them, or by absorbing them into their ranks - after faking their deaths, that is.

Due to the efforts to eliminate Demons across the multiverse, very few Demons exist anymore. Those who are discovered tend to either be killed quickly or forced to join the DKS.