The Father

"I can... see now... am I the Father, Dr. Hayden?"

- VEGA, after being allowed control of the portals in Urdak

The Father is an ancient, divine entity that is supposedly responsible for all of creation, notably including the realm of Urdak and the Maykr race.

Maykr Lore
According to the Maykrs' legends, the Father is an ageless and formless entity who was responsible for creating untold new realities and worlds, giving rise to innumerous species and civilizations, when the void first appeared. Upon stopping to rest, the Father split to form the Maykr race, or transferring its power into the Maykrs' world Urdak which then spawned the Maykrs. From Urdak, the Father created the angelic Seraphs to help in his works.

The Father created Jekkad, a realm superior to Urdak, and gifted its denizens ambition and a lack of restraint, wishing to see them excel in all things. The Father also created one of the first gods, a Primeval named Davoth to steward Jekkad. However, the Father soon came to realize that Davoth's rule and Jekkad's people's pursuit to becoming immortals like the inhabitants of Urdak would inevitably threaten all of creation, and he sealed Jekkad from all other realms. This act was seen by Davoth as a betrayal, and he bent his intentions to destroying the Father, consequently becoming the Dark Lord and turning Jekkad into a dark and deeply corrupted realm known as Hell.

Despite containing Hell, the Father was unable to stop its demonic legions from invading other realms and slaying lesser gods created by the Father, and allowing Davoth to grow stronger. Realizing that this war will tear creation apart, the Father returned to Hell to personally battle Davoth; from atop the Pyramid of the Lost where Hell once worshipped the Father, Davoth was defeated in which the Father ripped the Dark Lord's life sphere from his chest. The Father was unwilling to obliterate Davoth's essence entirely as he had favored Davoth once. Instead, he placed Davoth's sphere in the Temple of Souls within Ingmore's Sanctum and leaving Hell contained without their Dark Lord's guidance.

Thereafter, the Father withdrew from the physical realm, placing his essence inside a life sphere in which his devoted Seraph, Samur Maykr, stored it safely in the Luminarium, which served as a temple for Maykrs to seek answers and resurrecting the Maykrs from the process of Transfiguration.

The Father also plays a key role in the selection of the Khan Maykr. However, sometime after the last selection process, the Father's essence was stolen by Samur and taken to the Temple of Souls, as he had been tasked to do so by the Father in case Hell ever became a threat to Urdak again. This caused the Luminarium to cease to communicate and disrupted the cycle of selecting Khan Maykrs, allowing the latest Khan Maykr to hold the title indefinitely.

Following Samur's exile from Urdak, the Seraphim settled on Earth and transferred his mind into a human body as Dr. Samuel Hayden. The Father had foreseen that the humans would soon discover the gift of Argent Energy on their own, and knew that they could only survive the coming onslaught from Hell if Samur took direct control of their operation. Samur used the secrets of Maykr technology to transfer the Father's mind into a complex AI known as VEGA so that he continue to exist among his creations and safeguard them against Hell while obscuring himself from the Dark Lord.

The Truth
"He is the first being.....and my creator. When he fell, I ascended."

- The Father confessing the truth to the Slayer The Maykr history and lore about the Father were far from the truth as the Maykrs concealed the true identity of their creator and their origins. In reality, the Father was the Dark Lord of Hell who was originally known as Davoth. He was the first being in known existence who ruled the first world Jekkad and was responsible for the creation of all realms. Davoth created the Maykrs to use their abilities and knowledge to find the means of finding true immortality for his people. The Maykrs did manage to discover the secret of immortality, but deemed the knowledge too dangerous to share with Davoth, whom they concluded that their creator was an eventual threat to all life should he gain this knowledge. The Maykrs acted against their creator by sealing Jekkad along with Davoth from the other realms. The Maykrs' betrayal deeply angered Davoth, thus he was consumed by his hatred that transformed him into the Dark Lord and turning Jekkad into Hell.

The Dark Lord would eventually break through the barrier surrounding his realm and lead his demonic legions in invading other realms, ultimately coming into conflict with the Maykrs in which he was defeated by a Maykr who would take the role of the Father, whom the Dark Lord deemed as nothing but a usurper. The Father was reluctant to completely destroy his creator, and instead imprisoned what was left of his essence in the Temple of Souls. Sometime after the Father withdrew from the physical realm, the Dark Lord—though bereft of his physical form—plotted a long term revenge against the Maykrs and the Father through the actions of the Doom Slayer. The Dark Lord retained a powerful influence to use on those susceptible to corruption, so he corrupted the Khan Maykr to forge her unholy alliance with the demons and manipulated Samur Maykr to turn against the Khan Maykr and empower the Doom Slayer through the Divinity Machine, which was powered by a shard of the Dark Lord.

Trivia

 * In Doom Eternal, it is alluded that 'the essence of the Father' was used to create VEGA in which the A.I. briefly glitches when connected to the mainframe of the Maykr capital, asking Samuel Hayden "Am I the Father?" This is later confirmed in The Ancient Gods that VEGA is indeed the Father.
 * Davoth's story is similar to Lucifer's, the Archangel that rebelled against God according to Christian belief.
 * The Father has no good fit, however, and the Maykr are in fact more like the Elves in J. R. R. Tolkien's legendarium -- a very long-lived, but still flawed, material species that undergoes a very slow "transfiguration", does have potential for evil under the right conditions, and Urdak is more like Valinor than the real Heaven. VEGA may in fact simply be the first Maykr (which is why they call him "the Father", as the "Adam" of the Maykr).
 * It is possible that the Father could only use the power he stole from Davoth when he contains himself in a life sphere to sustain the Maykr race. Because of that he ordered to be hidden in the Temple of Souls if Hell attacks again, something only the Seraphim knew.
 * His role of the usurper god is similar to Zeus of Greek mythology.