The Ancient Gods, Part One

The Ancient Gods, Part One is the first single-player expansion for Doom Eternal, and was previously available as a pre-order item to purchasers of the Year One Pass. While some details appeared on the Steam store page for the season pass previously, the expansion was officially announced by Bethesda during the QuakeCon at Home stream on Twitch on, with release of a teaser trailer. A full reveal then followed during the GamesCom Opening Night Live event on August 27. It was released on October 20, 2020.

Story
Following the Doom Slayer's defeat of the Khan Maykr and the Icon of Sin and the salvation of Earth, the Slayer learns that Urdak has since been overrun by the forces of Hell, which plan to use it as a staging ground for their conquest of reality. To return to Urdak and save the fallen paradise, the Slayer, aided by the ARC, reunites with the Seraphim (here revealed to be the secret identity of Samuel Hayden), who informs him that it is time for the Slayer to "serve the gods yet again".

At the Seraphim's direction, the Slayer travels to the Blood Swamps to reach the Ingmore Sanctum, where the Father's life sphere is hidden. The Seraphim expects the Slayer to recover the sphere and bring it back to the Luminarium so the Father might be restored, but instead he destroys the Father's life sphere and recovers the life sphere of the Dark Lord, so he might force the demonic overlord into a physical form that can be destroyed to end the threat Hell poses to the universe.

The Slayer fights his way through the corrupted Urdak, eventually confronting the Transfiguration-afflicted Seraphim within the Luminarium. The Slayer is victorious over his former ally in the ensuing battle, but before he can strike the killing blow the Seraphim is teleported away by the Father, who tacitly approves of the Slayer's self-imposed mission. As the Dark Lord is resurrected, his body is revealed to be a perfect copy of the Slayer, at which point the story ends with the note "To Be Continued".

New enemies
The expansion adds the following enemies to the Doom Eternal roster:


 * The Blood Maykr, a corrupted Maykr angel wearing red armor and possessing demonic horns, able to fly and attack with its staff. It can charge up its energy in a cruciform display, enabling strong armor which protects its otherwise vulnerable head. Unlike normal Maykr angels, their faces are exposed.
 * The spirit, a ghostly variant of the summoner from Doom (2016). It can possess other demons, preventing their weak points (if any) from being broken and protecting them from faltering; possessed demons also gain significant resistance to damage from the ballista, become significantly faster, and have additional hit points. To defeat the spirit, the host must be killed and then the spirit itself must be eliminated via use of the plasma rifle's microwave beam mod before it can find a new host. Spirits cannot attack on their own and will disappear if they cannot find another demon to possess.
 * The turret, similar to the eyes of Kalibas and those previously found near the top of the Nekravol. They possess dedicated pillar-like shelters that they pop in and out of, rapidly firing energy bolts at the Slayer.
 * The whiplash spectre, an invisible version of the whiplash similar to the spectre.
 * The Trial of Maligog, special turrets fused with punch blocks which can fly and whose attacks slow down the Slayer. Four of them are fought in a boss battle in the Blood Swamps.
 * Samur Maykr, the Seraphim, changed into a demon-like creature by the Transfiguration. He is the end boss of the DLC.

Levels

 * UAC Atlantica Facility
 * ARC Carrier
 * The Blood Swamps
 * The Holt