Fel



Fel magic is a destructive form of magic often used by demons and the members of the Burning Legion. It is demonic, entropic, chaotic and extremely volatile. Its use by the wielder, or its effects on the victim, frequently results in an alteration of the individual, colloquially called corruption. All of the Burning Legion carry the taint of fel magic within their very blood, allowing them to spread greater evil. While fel is the language of chaos and disorder, arcane represents order, and are considered opposite ends of the same spectrum.

Origins and characteristics
Order is most commonly perceived in reality as arcane magic. Arcane energy is innately volatile, and wielding it requires intense precision and concentration. Disorder, on the other hand, manifests as highly destructive fel magic, a destructive and extremely addictive energy originating as a result of the mutual destruction of Light and Void as they collide on a cosmic scale in the Twisting Nether. Fel is fueled by drawing life from living beings and consuming their souls, utterly destroying them in the process. It requires but an insignificant sacrifice—a living fish or two, a few strands of seaweed—to fuel the magic.

When a soul is devoured by fel energies, it produces more fel and is utterly destroyed in the process. Lesser warlocks must use a soul shard (or soul fragment) to summon minor demons. Soul shards can be used to power spells, or to create a connection to the Twisting Nether, pulling a demon through against its will.

Fel energy counters and is countered by arcane energy, its polar opposite. Fel works like radiation, permeating an area and seeping into anything in the vicinity. Anything near a source of fel energy will eventually show signs of slight corruption. It smells like sulfur and brimstone. Fel can also pool into a green goop when it's in physical form. Pit lord blood is literal fel goo. When drank, their blood causes mutations such as the growth of spikes, horns, scales, and wings. Felfire is flame born of fel magic. It is deadly to the touch, burns much hotter than normal fire, and cannot be put out by regular means, though the water of enchanted water elementals seems to be able to do the trick. A scalding core of fel fire is what powers the fel reavers of the Legion.

Fel, like all other types of magic, can be animated. An example of this are the Flames of Azzinoth. Fel is mainly used to cause massive destruction by its wielders. But it can also be used to turn oneself invisible, to scry, and to create portals much more efficient, long-lasting and easier to create than with arcane magic. It can be used to give momentum and propel a boat for example, and is used to power the monstrous machines of the Burning Legion. Fel can also be used to heal, though it leaves a mark on creatures who are not fel-based. It can also be used to breathe life into constructs such as infernals, or in a necromantic way by resurrecting demons as undead.

The demon hunter Illidan Stormrage now bleeds green blood.

Effects on beings
Infusion with fel magic, also called fel corruption, can manifest with positive effects in which case it can be considered a gift, or a blessing, like that of the eredar, or with negative ones in which case it can be considered a curse. Physical transformation normally ensues, such as a change to an individual's eyes or skin color, or heavy genetic mutations such as the growth of demonic traits like spikes, scales, and horns. Negative corruption tends to lead to physical or mental deterioration, as happened with the draenei that turned into Broken and Lost Ones, or as happened with boars turned into enraged hellboars.

Either way, corruption gives the individual increased strength, more magical potential, and can lead to transformation into a demon. Warlocks with long exposure to or with extensive use of fel magic age faster than normal, and become physically weaker over time. Fel seems to tend to cloud one's judgment, or at least heavily amplify their negative traits such as violence and impatience while snuffing out positive ones such as empathy, allowing one to make decisions they never would've made before.

As the existence of non-sentient demons suggests, a creature's wishes are irrelevant to the process. Willing or not, a creature can be changed into a demon.

Demons

 * ...fel energies: the dark magic of demons, all corrupting and all-consuming if the craving for it was not held in check.

Demon souls are tethered to the Twisting Nether and as such, even if a demon dies in the physical universe, their spirit will return to the Nether where they will reform once again. To truly destroy a demon, the creature must be killed in the Nether itself, in places where it bleeds into mortal worlds, or in areas saturated with fel energies. Demons normally delight in inflicting suffering, spreading corruption and destroying all that is good. Mortal beings can be turned into demons themselves by being infused with fel energy, the dark and corrupting essence wielded by the Burning Legion.

Eredar and draenei

 * Sargeras infused the eredar with fel energy, turning them into demons, now called Man'ari eredar, and found quick use for his new fel-corrupted converts. The eredar settled in as commanders within the Burning Legion. Under the eredar's leadership, the ranks of the Burning Legion swelled with new demonic races, gathered from the Twisting Nether and the worlds of the Great Dark Beyond.
 * Some man'ari became wrathguards.


 * The Old Horde brought the Red mist upon the draenei, causing them to mutate and devolve into the Broken and then further into Lost Ones. Their warped bodies bear only a rough resemblance to the proud draenei they once were, and quite a few have lost their grip on sanity.

Orcs

 * Gul'dan was the first orc warlock and is considered one of the most powerful mortal warlocks to have ever existed. He taught other young orcs the arcane arts and strove to eradicate the orcs' shamanistic traditions. Kil'jaeden, seeking to tighten his hold over the orcs, helped Gul'dan found the Shadow Council, a secretive sect that manipulated the clans and spread the use of fel magic throughout Draenor. As more and more orcs began to wield warlock magics, the gentle fields and streams of Draenor began to blacken and fade. From every account, the demonic energies, used so freely and with no heed given as to their cost, leeched all that was wholesome and life-giving from the world of Draenor.
 * The originally brown orcs changed from under the influence of Mannoroth's blood, their skin became various shades of green and they began experiencing lusts for blood.
 * Orcs that kept drinking pit lord blood became fel orcs.

Elves

 * Blood elves are high elves who had temporarily turned to absorbing demonic magic after the loss of the Sunwell, and had subsequently become addicted to the fel energies. From the most pious of priests or most outdoorsy of Farstriders, chances are any high elf in Quel'Thalas or Outland following the Third War was around fel energies, which made their eyes turn green. Kael'thas Sunstrider's most loyal followers were rewarded by Kil'jaeden with the gift of being allowed to gorge themselves on demonic blood for days for remaining in Outland, even as many of his blood elves retreated through the Dark Portal. These are known as Felblood elves.
 * Satyrs have been transformed into their current shapes by inheriting the demonic curse that originated with Xavius.

Titans
Titans are naturally vulnerable to fel magic. When Sargeras was infused and deformed by the explosion of fel energy caused by the shattering of Mardum, the Pantheon could not overcome Sargeras's fel-fueled might. The fallen titan decimated the Pantheon members by summoning a massive fel storm that would consume their bodies and souls alike, though Norgannon managed to save their souls and made them flee towards Azeroth, where they would vanish.

Void revenants
Void revenants are a race of parasitic void-beings that tear holes through the planes of reality, consuming and absorbing the energies and beings within. Xhul'horac was twisted and fed overwhelming fel energy by alternate Gul'dan and wanted to use his powers to tear open the portals through which he planned to rally the forces of the Burning Legion.

Demon hunters
Demon hunters, disciples of Illidan Stormrage, uphold a dark legacy, one that frightens their allies and enemies alike. The Illidari embrace fel and chaotic magics—energies that have long threatened the world of Azeroth—believing them necessary to challenge the Burning Legion. Wielding the powers of demons they've slain, they develop demonic features that incite revulsion and dread in fellow elves. Demon hunters mark their bodies with arcane runes to keep their fel forces in check.

Druids
Some druids have manipulated fel energy to enhance their attunement with the wild.

Mages
Some mages gave up the arcane to begin a personal quest to understand demons and their fel energies, like Daio the Decrepit, effectively becoming warlocks. Some warlocks are also named fel magus such as Fel Magus Verondis and Fel Magus Kel'rothek.

Dalaran attempts to stifle the studies of fel magics and necromancy. Despite the superior power of fel magic which threatened to overshadow established practices, students were taught about practicality over what is achievable. Fel's efficiency is commonly balked for being unstable and "evil". The official teachings of the Kirin Tor are that demonology is to be eschewed, avoided, and abjured. Any attempt to summon demons are to be found out and stopped at once, and those involved are to be expelled, or worse.

Warlocks


Warlocks are magical practitioners that seek to understand darker, fel-based magic, and its destructive spells. While many warlocks willingly follow the Burning Legion, there are those who work against it, using their magic to fight against evil. Warlocks have proven themselves to be powerful allies-as well as powerful foes. Warlocks convert life into fel, draining the victim as a source of power.

Entropic horrors
Fel energy can manifest as entropic horrors, pure fel magic given form to lash out at all life. The essence they drop is poisonous and would poison living beings with a sickness that drains life.

Others
Any creature can be corrupted with fel magic, including dragons, harpies, tauren, murlocs, arakkoa, animals such as hounds, wolves, boars, and so on.

When the human Malus took Xaraax's fel sword, it empowered and transformed him, his eyes blazed green with corruption. He stated that the fel flames whisper to him of victory and destruction.

In the RPG
The ultimate manifestation of the demonic arcane on Azeroth is fel energy. Fel energy, which most commonly manifests itself as ghastly, green-yellow flame, is arcane magic at its most corrupt, for it employs the blood of demons. Unlike arcane magic the use of fel magic corrupts the user's body and soul. By contrast, the chief danger of arcane magic is that using it inevitably leads to the desire to wield greater power: power that only fel magic can provide. When the demons brought death and damnation to Azeroth, they also carried their own brand of magic to the world. Fel magic is pure, evil and arcane; it resides in the blood of demons. This blood has magical properties; it is addictive to arcane magic users and can be used to create evil weapons. When a weapon is forged in demon blood, it becomes a fel weapon. It glows with a foul, yellow-green fire and deals extra damage to good-aligned opponents. Some arcanists can cast fel spells, perhaps after drinking demon blood. Since the Burning Legion returned to Azeroth, the world's heroes have encountered fel weapons and fel magic at an increasing frequency. As demon cults continue to fester and grow in Desolace, Ashenvale Forest, and other remote corners, gruesome sacrifices are held to entice demons into giving their blood in trade. The cultists use their blood to enchant the weapons that they hope will bring about their masters' ultimate victory.

Demons sometimes tempt spellcasters by offering small amounts of their blood in exchange for services. If the recipient drinks the demon's blood within 24 hours of the offering, the next arcane spell he casts will be empowered by the fel. Fel blood is highly addictive as well as corruptive. Anyone who drinks it risks becoming dependent on fel blood, and unless the person continues to drink it daily, he will suffer withdrawal symptoms. He has a chance of breaking the addiction seven days after first drinking the fel blood.

Spells with the fel descriptor are very difficult to resist. Casting a fel spell is described by many spellcasters as a euphoric experience. If arcane magic is an addiction, fel magic is the embodiment of the drug in its purest form.

Entropic fire
Entropic fire is fel energy given substance: it is entropic fire that burns on infernals, and it is entropic fire that ran down the body of the pit lord Mannoroth the Destructor. Entropic fire burns, as does normal fire, but it is more sinister still: it feeds on life, including the life of its wielder.

Fel stone
A gray ore known as fel stone litters the physical spaces of the Nether. It functions as a conduit for the Nether's entropic energies.

Notes and trivia

 * The fel reavers of the Burning Legion are powered by a scalding core of felfire.
 * Warlock players can complete a quest chain to infuse their fire spells with entropic, green fel magic.
 * Matt Burns believes that "hellfire" is a more general term for felfire.
 * Fel has been used as an expletive by characters in-universe in a similar manner to "hell". Rehgar Earthfury once demanded "What the fel is wrong with you?" to Thrall, and Zhahara Darksquall has proclaimed "Who the fel?" However, the more conventional "hell" remains much more commonly used.
 * In Shadows of the Horde, Vol'jin uses "fel" as a descriptor for things that are ominous or wrong (similar to the word "fell"), even things that are unrelated to actual fel magic.