Argent Energy

"The demons only utilize a portion of the resources that come from the human soul. It was the Maykrs and the Sentinel Priests who discovered and unlocked the true power of the Essence. They combined Sentinel and Hell energies together, refined it, and created... Argent."

- Samuel Hayden

Argent Energy is a new form of renewable energy that was discovered by the Union Aerospace Corporation in the late 21st century. It is produced by neutron activation of Argent Plasma. Publicly, Argent Energy was believed to originate on Mars, but in reality, it is secretly mined from Hell, where the element is innately tied to that realm and its demonic inhabitants.

In Doom Eternal, Argent Energy is discovered to be none other than the combination of Sentinel energy and Hell Essence, which is made from tortured souls torn from the bodies of freshly dead mortals trapped in Hell. It's then purified by the ancient Wraiths using Maykr technology to feed Hell's legions and Urdak's Maykrs while the husks of the victims left behind are turned into demons.

History
The demons of Hell feed on a volatile aura called the Essence that invigorate themselves for battle. This aura is derived from the transformation process of mortal creatures into demons. As the mortal slowly transforms, the ethereal soul slowly drains from the body and manifest as matter, which gathered in pools containing Essence known by demon-kind as The Well. However, the demons only utilized a portion of the resources that come from the human soul as it takes eons for mortals to change into demons, and therefore more time-consuming to harvest the Essence.

At some point it was discovered either by demonkind or the Maykrs that by torturing the souls that were sent to Hell they could not only speed up the transformation progress, but also produce much more Hell Essence.

The Maykrs and Sentinel Priests first came to realize the true potential of the Essence during the first Hell invasion on Argent D'Nur; they combined Hell and Wraith energies together, refining it, and created Argent. The Maykrs saw Argent as the key to prolonging their life span and preventing their natural physical and mental degeneration (a process more commonly known as Transfiguration), and the Khan Maykr struck an unholy deal with the Dark Lord of Hell: in return for access to more worlds for Hell to devour, the Maykrs siphoned energy from the damned to be processed into Argent Energy.

By the bidding of the Khan Maykr, the Order of the Deag devised a method to improve and accelerate the production of Hell aura: through slave labor, the Deag Priests built the Soul Spires, constructs that torture the bodies of those killed and taken to Hell by the demons. The spires torture and mutilate the trapped mortal victims (who, despite being dead, can still feel pain - presumably due to the very nature of Hell itself) until no semblance of humanity remains within them. Once drained of all hope, the vulnerable souls are easily extracted via the Maykr-made Evulsor. After the procedure, the victim's now soulless body is ejected into Hell's wastelands, where it will transform into a demon over time. The main site of Argent processing is the city of Nekravol, where the flow of Argent Energy is directly teleported to Urdak.

At some point during their war against Hell, the Night Sentinels discovered the horrifying secret behind Argent Energy when a company of their soldiers came across one of Hell's secret soul factories. Inside the factory, the Sentinels found the corpses of the recently fallen being processed and tortured, their souls being drained and turned into Argent Energy by machines of Makyr design, and their empty bodies discarded to become demons themselves. The Sentinels attempted to warn their people of the Khan Makyr's treachery, but many either didn't believe them or didn't care, as the Argenta had grown dependent on Argent Energy and willingly sided with the Maykrs’ atrocities. During the final days of the war, the Sentinels decided to attack Nekravol itself and destroy the primary source of Argent Energy. However, this plan was thwarted when the Deag Priests manipulated the dimensional portals to Hell, causing the Sentinels to become separated from each other and scattered across Hell, and allowing the numerous demons to pick them off one by one, with only the Doom Slayer surviving the trap.

Discovery by the UAC
The UAC discovered Argent Plasma in 2095 during a geological survey mission in the Promethei Terra region of Mars, in a narrow trench which later dubbed as the "Argent Fracture." The corporation discovered ancient artifacts within the Argent Fracture, among of them was the Helix Stone, which allowed the UAC to learn how to harness and manipulate Argent Plasma. Within a year, the UAC established an outpost to extract Argent Plasma and subjected it to the Fermionic Transference Pattern, producing Argent Energy.

Within a span of two decades, Argent Energy revolutionized human society as it met their energy requirements, allowing it to be integrated into all forms of technology to the point of becoming practically ubiquitous. As a result, oil, nuclear and solar energy were rendered obsolete due to Argent Energy's unlimited source and high energy efficiency.

The UAC strictly kept the origins and production of Argent Energy secret from the public including the Global Science Council, keeping them from learning about the existence of Hell, and as well bottlenecking the production of Argent Energy to maintain their control over the market value.

In 2149, the UAC Mars base lost all communication from Earth when it was overrun by demons. The Doom Slayer prevented the Hell invasion by destroying The Well. But events on Mars left Earth deprived of the miraculous power source, leading to an energy crisis that coincided with a renewed Hell invasion on the planet. However, Dr. Samuel Hayden possessed humanity's last remaining source of Argent Energy in existence in the form of the Crucible; using the artifact's hidden power, Hayden used The Crucible as an Argent conductor to produce synthetic, man-made Argent Energy, and restoring the production of Argent Energy to Earth, albeit at the cost of paving the way for the demonic invasion of Earth.

The Doom Slayer later traveled to Nekravol in order to reach Urdak. He climbed to the top of Nekravol's Argent Energy transmitter and teleported himself to Urdak via the Argent Energy flow. After the death of the Khan Maykr and her violation of her pact with Hell, Argent production is presumably shut down, with the Slayer's Crucible plunged into the Icon of Sin's brain.

Properties
Found in Hell, Argent Energy's metaphysical nature defies previous laws of physics on other forms of plasma. While plasma itself is a superheated gas to the point of freeing electrons to become ionized, Argent Energy seems to be stable at higher than thought possible temperatures and can energize objects it comes into contact with.

Trivia

 * Although being pinkish-orange or bright red in its natural form, the word Argent itself means silver or white, being a tincture of silver. It was often used on symbols of heraldry. It derives from Latin argentum, again meaning silver.
 * Ironically, silver is believed to dispel demons and to heal diseases in many cultures, but Argent is an energy harvested from Hell and used by demons.
 * In Doom (2016) it's shown Argent energy is filtered and purified to be blue/white, against its raw form.
 * Coincidentally, the Chinese version of Doom (2016) translates Argent as "亞金," which means "second to gold/inferior than gold," possibly chosen because it reads as yà jīn, which is a loose transliteration of "Argent" into Chinese.
 * There is apparently an easter egg for Argent energy and Doom's portal technology mentioned in Wolfenstein II: The New Colossus that has led to further speculation that the universe of Doom (2016) takes place in the future of MachineGames' Wolfenstein series