Demons, sometimes translated into "Twisted Souls" are a composite species of immortal entities that exist throughout the Twisting Nether. Demons delight in inflicting suffering, pain, spreading corruption, and destruction. Demons are entropy in the highest function, a fundamental antithesis to the heights of order and creation, and all Demons, no matter their elegance, exist to spread and feed their corruption across the Great Dark Beyond.
The history of Demons is a long one that stretches back far before the ordering of Azeroth, and while their exact origin is unknown, Demons are propagated, and propagate by, empowering themselves with the chaotic energy known universally as 'Fel'.
Demons are a composite species, meaning that there is no singular genus within the Demon species. Most Demons that exist in the universe today are converted mortals from worlds conquered by the Burning Legion, the Felguard being a prime example of such. However, not all Demons come into existence this way. Demons inevitably will come into existence wherever there is the presence of the cosmos spanning energy known as 'Fel.'
Fel's origin is unknown, and dates back far beyond Sargeras was corrupted into the Lord of the Burning Legion. What is known is that Fel Energy and Demons share a symbiotic relationship. Demons are incapable of reproducing naturally, and instead produce Fel energy within their bodies. This energy can escape their bodies through various means, such as an intentional projection, or a expulsion upon death, and can begin converting non-demonic species into Demons.
There is an important distinction between Demon-corrupted species and Demons themselves. Demon corrupted species such as the Fel Orc or Felblood Elf share many of the same qualities as Demons, including an increase in strength, size and the creation of uncontrollable mutations in the presence of Fel Energy. A True Demon however, is immortal upon the material plane of the universe, and their Demonic 'soul' if such a thing exists, can only be destroyed within the Twisting Nether. Demon-corrupted races are still mortal creatures and can perish upon the material plane as easily as mortal races.
- See main article: Races of the Legion
Demons have a great many varieties of sub-species within their kin, and many more can be corrupted or converted from existing mortal species. The most common of Demonic species, and some more unique examples, can be found here:
- Dark Titan
- Fel Beast
- Imp Mother
- Fel Imp
- Man'ari Eredar
- Doom Lord
- Void Terror
In ancient times, Demonic Species were utilized by the Titans as a servant race. Demons such as the Terrorfiends and the Doomguard were hounds for the Titans, tasked with policing the worlds of the Great Dark Beyond against the foulest of magics, and none were so sweet to Demonkind as sacrificial magic. Eventually, Demons were marshaled into an organized army by the Demonic species of the Nathrezim and the Annihilan, and began spreading their corruption to other worlds of the cosmos. To combat this threat, The Titan Pantheon selected their Greatest Warrior, Sargeras the Defender, to combat this evil. Sargeras waged a lengthy war against the Demons that sought to bring ruin to the Titans perfect order, and eventually ended their threat. The Titan imprisoned trillions of Demons upon the Titan prison world of Mardum.
Unfortunately, this defeat for the Demons was merely the precursor to an even greater age of strife for the universe. The corruption and evil of the very Demons Sargeras had defeated affected him deeply, and fell into a great depression, unable to comprehend the Titans perfect order in which existed a race of chaos such as the Demons. Beginning to believe that chaos was the very order that the Titans had tried to deny, he drifted far from his brothers and eventually left the Pantheon altogether.
Sargeras shattered the Demonic prisons of Mardum, freeing their legions upon legions of prisoners. He recruited the very Demons he has imprisoned in his fight against them to form a new army. In time, the fallen Titan's vision for the future took form in the shape of a Legion. A burning crusade that would restore the Universe to the Chaos that had existed at its dawn.
Sargeras and the Eredar
An indeterminate amount of time after Sargeras fell to madness, the planet of Argus was contacted by the dark Titan. The Eredar were originally a race of great intelligence, where science, magic, and religion melded together. The Eredar were led by Kil'jaeden, Archimonde, and Velen.
The three great Eredar were contacted by Sargeras, and promised a great civilization filled with thousands of worlds and adoring subjects. Kil'jaeden and Archimonde were convinced, but Velen was not. Receiving a message from the Naaru, Velen realized that Sargeras was attempting to deceive his brothers. Velen and those loyal to him exiled themselves from Argus, with the now corrupted Eredar in pursuit.
The Well of Eternity
15,000 years after the Draenei escaped from Argus, Azeroth had entered a time of relative peace. The Nerubian and Qiraji forces were pushed to the northern and southern lands of Kalimdor, the Trolls were pushed away, and the Highborne empire prospered. This Utopian society was aided by the Well of Eternity, a magical source of power that was the base for the Highborne's immortality.
Sargeras, seeing the power of the Well and the potential strength he could gain, contacted the queen of the Highborne, Azshara, through her counselor. He proposed a future of Azeroth wiped clean, so the Kaldorei could rule supreme. In her lust for power, she accepted.
With the assistance of Illidan Stormrage, Tyrande Whisperwind, and Malfurion Stormrage, the Demons were pushed back. With the final assistance of Red Dragons and Rhonin, and the sacrifice of Broxigar to damage Sargeras, the demons were repelled. However, the chaotic energies caused by the Fel disturbances sent the pool out of balance, ending in a cataclysmic explosion.
The result of the explosion created the four main continents of Azeroth, alongside the several islands around the world. The remains of the Highborne empire mainly lay in the western continent of Kalimdor, and on the Broken Isles.
The Third War
Relative peace came to Azeroth until Arthas, the Scourge, and the third demonic invasion of Azeroth. The prince of Lordaeron, Arthas Menethil, was one of the forefront of combatants against the scourge. Caused by Ner'zhul's chaining to the Helm of Dominion, the scourge was created by the Cult of the Damned. This cult went about plaguing the grain with a disease that would turn humans into scourge. Arthas, young and full of energy, sought to wipe their taint off the face of Azeroth forever.
In his eager quest for vengeance against the Scourge, Arthas purged the human city of Stratholme, where he encountered the Dreadlord Mal'ganis. Mal'ganis later corrupted Arthas into doing the Legion's bidding as a champion of the scourge. Through a long series of events, Arthas betrayed Lordaeron. He killed his father, Terenas Menethil, and destroyed the rest of the city. He then set off to the north to ressurect Kel'thuzad using the Sunwell, who would in turn summon Archimonde into Azeroth.
After the Burning Legion's third in command, Archimonde, was summoned in Dalaran the world was plunged into the third demonic invasion. The warsong orcs under Grommash Hellscream, re-corrupted alongside the other demons, fought against the combined force of the un-corrupted orcs, Lordaeron survivors, and the Night Elves. Through a long battle for the World Tree, Archimonde was killed on the slopes of Mount Hyjal. His lieutenant Mannoroth was killed by Grommash Hellscream.
With the death of the two Legion commanders, the demon forces were pushed to small encampments in Kalimdor and the Eastern Kingdoms. A full on invasion has not happened again, but recent events in Draenor have brought the possibility of a Fourth Invasion into people's minds.
A common mistake made by scholars is calling a demon a mortal. They are immortal in a traditional sense, but their physical form can be banished. The only way a demon can actually be killed is if their form is destroyed in the twisting nether.
Demon physiology varies between the species, often being very twisted versions of other creatures. Felhounds, for example, appear to be similar to a mastiff crossed with a lizard. Fel Guards look like humans, but with exaggerated proportions and large spikes coming out of their head. This corrupted form is caused by the magic of Fel.