Urdak

Urdak, also known as Heaven, is the realm of the Maykr race and domain of the Khan Maykr. A hub of transcendent technology, the whole city is powered by a purified form of Argent Energy. According to legends, Urdak is considered to be a living being made of the souls of past Maykrs.

History
According to Maykr lore, Urdak was created from the remains of the Maykrs' progenitor known as The Father, as his body was fractured, transferring his incalculable power into Urdak's vast structure which then birthed the Maykr race.

It has been stated that although Urdak looks of angelic origin, it is not really Heaven nor contains many prominent supernatural elements like Hell, with the realm being mostly a technologically-driven domain and the Maykrs themselves being mortal beings prolonging their lifespans through using Argent Energy. However the denizens of Urdak would use their technological superiority to take on the guise of a local planet's native religious figures in order to subjugate and essentially vassalize 'lesser' civilizations, posing as their native gods and offering technological enlightenment in return for other species' servitude while under this guise. Having done so most notably with the culture of the Argent D'Nur who themselves conquered many worlds for the Maykrs.

Urdak, like Hell, is in another dimension to "our" Universe; however this was not always the case, as unlike Hell's actual status as an otherworldly realm, the Maykr achieved Urdak's placement into another dimension by utilizing highly advanced dimensional shift technology to escape into their own dimension outside the regular boundaries. Other than moving Urdak to its own dimension, this technology allowed it to exist in an anchor state, i.e. in a static position at a sub-quantum level. This essentially inverts Urdak's position in relation to Hell, meaning these planes of existence are fixed "outside" of the bounds of the known universe, which makes the Maykr refer to them as 'lower' and 'higher' reality.

At some point in their history, a rogue Maykr known as the Seraphim betrayed Urdak and stole The Father's essence, which damaged the Maykrs' Transfiguration process and greatly crippled the whole of Urdak.

Urdak ultimately fell to invasion from Hell due to the Khan Maykr's attempt to awaken the Icon of Sin within the city and the Doom Slayer's interruption of the awakening; The Slayer destroyed the Icon of Sin's heart, which allowed the Khan Maykr to contain and control the demon, and causing the Icon to break free and unsealing the barrier between Urdak and Hell. The demons of Hell immediately ended their pact with the Maykrs and invaded Urdak.