Story for DOOM 2016 and DOOM Eternal + DLCs

The game is set on Mars, with a UAC facility being invaded by the forces of Hell. The Doom Slayer awakens chained to a sarcophagus in a UAC facility. Breaking free and regaining his "Praetor Suit", he crosses the Martian surface to restart the base satellite systems. Finding recordings of Dr. Olivia Pierce[4] scattered through the base, it becomes apparent that she became fixated on Hell and deliberately encouraged the opening of portals, resulting in the mass death of staff and the collapse of the base. Contacted by the UAC Chairman Samuel Hayden, one of the few survivors of the incident, the protagonist is directed through the base to prevent its complete collapse. With the guidance of Hayden and an AI called VEGA he learns from the diagnostic report that casualties and damages are catastrophic; with the exception of Pierce and Hayden, all staff have either become demons or died horribly. After stabilizing the Foundry before a meltdown occurs, Doomguy learns that Pierce plans to use the UAC's Argent Energy Tower to tear a permanent portal into Hell. Seeking to deactivate the tower, Hayden instructs Doomguy to carefully dismantle the Argent energy supply cases to protect the unlimited energy sources; despite Hayden's protests, Doomguy shatters all control panels and their lenses, completely destroying the renewable Argent supplies in the solar system. Reaching the tower, Pierce is spotted carrying an Argent Accumulator tube; found at the apex, she activates it before jumping into an Argent stream, tearing open a temporary portal that drags the player to Hell. Landing in the Kadingir Sanctum, the player has to fight through the forces of Hell in order to return to Mars. Following holograms of Hayden's first expedition, during which he recovered Doomguy's sarcophagus as a failsafe, Doomguy eventually reaches a portal back to Mars. Returning to the UAC Argent Facility, now destroyed, he meets with Hayden, who applies a tether system to his Praetor Suit in order to pull him back from Hell as needed. Noting that Pierce was working on something with great power, he sends Doomguy to gather information from her office in the Lazarus Labs. Passing through the Advanced Research Complex, Doomguy learns of a Hell artifact named the Crucible. Requiring another Argent Accumulator to return to Hell, Doomguy explores the Lazarus Labs and comes across an escaped Cyberdemon; rebuilt and revived with Argent energy, he defeats the Cyberdemon and tears an Accumulator from its chest, transporting them both to Hell where he finishes the Cyberdemon. Pushing deeper into Hell, Doomguy finally reaches the Necropolis. Defeating the Hell Guard watching over it, Doomguy retrieves The Crucible before Hayden pulls him back to Mars. Arriving at VEGA Central Processing, the AI guides him through the process of sacrificing his control facility, allowing him to use its huge Argent stores in order to propel him back to Hell one last time. Using The Crucible, Doomguy destroys the energy sources powering portals between Hell and Mars, and enters the depths of Argent D'Nur. Reaching the end, he finds only Olivia Pierce, horrified at the realization she was merely a pawn. Struck by a large Argent beam, she transforms into the Spider Mastermind, eventually dying at Doomguy's hand. Pulled back to Mars, Doomguy finds himself captured by Hayden. Taking The Crucible for his own ends, he insists that, in spite of everything, research must continue, as humanity needs an answer to its energy needs. Since he can't kill Doomguy, but worries of his interference, he has him transported to an unknown location, saying they will meet again.

Some time after the events of Doom (2016), Earth has been overrun by demonic forces, wiping out 60% of the planet's population, under the now-corrupted Union Aerospace Corporation. What remains of humanity has either fled Earth or have banded together as part of ARC, a resistance movement formed to stop the invasion but have gone into hiding after suffering heavy losses. The Doom Slayer, having previously been betrayed and teleported away by Dr. Samuel Hayden, returns with a satellite fortress controlled by the AI VEGA to quell the demonic invasion by killing the Hell Priests: Deags Nilox, Ranak, and Grav. The priests serve an angelic being known as the Khan Maykr who seeks to sacrifice mankind. The Slayer teleports to a destroyed city in California and kills Deag Nilox, but the Khan Maykr teleports the two remaining priests to unknown locations, forcing the Slayer to continue searching. After retrieving a celestial locator from the Sentinel world of Exultia, the Slayer travels to Hell to retrieve a power source from a fallen Sentinel known as the Betrayer. He warns the Slayer that humanity's time has come before giving him the power source and a special dagger. VEGA directs the Slayer to a citadel in the Arctic where Deag Ranak has taken refuge, and the Slayer kills him after defeating his guardian Doom Hunters. In response, the Khan Maykr moves Deag Grav to a hidden location and accelerates the invasion of Earth. Forced to change tactics, the Slayer destroys the Super Gore Nest in central Europe, where the invasion began. With no leads on finding the last Hell Priest, VEGA suggests finding Dr. Hayden, who knows the location of Deag Grav. The Slayer makes his way to an ARC compound where he retrieves Hayden's robotic shell, as well as the Crucible before facing a Marauder, a demonic Sentinel sent to stop the Slayer. Upon uploading Hayden's mind into the fortress, he reveals Deag Grav is hiding on Sentinel Prime. With the only portal to Sentinel Prime located in the ancient city of Hebeth in Mars' core, to which there is no immediate access. The Slayer then travels to a facility on Phobos where he uses the BFG 10000 to shoot a hole in Mars, which he uses to reach Hebeth. After reaching Sentinel Prime, flashbacks reveal the Slayer to be Doomguy. Found badly wounded by Sentinels, Doomguy was brought before the Deags and was forced to fight in a gladiatorial arena. Impressed by Doomguy’s ruthlessness in battle, the Deags inducted him into the Sentinels, while the Khan Maykr inquires into Doomguy's knowledge of the Demons. In the present, the Slayer finds Deag Grav in the arena and defeats a massive demon known as the Gladiator. Despite knowing that it is against Sentinel law to murder Deag Grav on sacred ground, the Slayer kills him anyway and returns to the fortress. Upon his return, the Slayer's fortress is shut down remotely by the Khan Maykr to prevent any further interference in her plans. She reveals her intentions to resurrect the Icon of Sin, the world-eating super-predator, to consume mankind before having the Slayer attacked by demons. Surviving the ambush, the Slayer uses the demonic Crucible's latent Argent energy to reactivate the fortress and travels to Argent d'Nur to retrieve his own Crucible from his time in the Sentinels. Further flashbacks reveal that during the ill-fated battle of Argent D'Nur, a rogue Maykr known as the Seraphim had imbued Doomguy with superhuman abilities, transforming him into the Doom Slayer. After retrieving the hilt of the Crucible, it is revealed that the Khan Maykr formed an alliance with Hell to produce Argent energy, which is created through the mass sacrifice of human souls. In return for providing worlds for Hell to invade, the Maykrs receive a share of the Argent energy produced by Hell which allows their own dimension, Urdak, to survive. Hayden directs the Slayer through Hell's massive citadel, Nekravol, until he finds a portal leading to the Urdak. He then finds the Khan Maykr and halts the awakening ceremony by using the Betrayer's dagger to destroy the Icon's heart. Free from Maykr control, the Icon of Sin awakens from its dormant state and teleports to Earth. With the dimensional barrier destroyed, the Demons break their pact with the Maykrs and proceed to invade Urdak. The Khan Maykr confronts the Slayer, saying that Urdak must destroy Earth to survive. They battle and the Slayer kills the Khan Maykr before taking a portal back to Earth to confront the Icon of Sin, although VEGA is left behind to ensure the portal stays open. After an intense battle across the cityscape, the Slayer kills the Icon of Sin by stabbing it in the head with the Crucible, putting an end to Hell's invasion of Earth. As the Slayer walks away, King Novik, leader of the Night Sentinels, states how the Slayer's fight is "eternal".

Despite having defeated the Icon of Sin and halting Hell’s invasion of Earth, the Doom Slayer’s victory over the demons did not come without cost. The death of the Khan Maykr and Hell’s conquest of Urdak have given the demons a chance to dominate all dimensions and reinitiate their invasion of Earth. To prevent this, the Doom Slayer, along with Samuel Hayden and ARC scientists, embark on a mission to find and liberate the Slayer’s ally, the Seraphim. Traveling by sea on an ARC Carrier towards the UAC Atlantica Facility, the Slayer fights his way to the Seraphim's containment pod. When Hayden requests he be uploaded into the pod, it is revealed that he and the Seraphim are one and the same. After returning to the ARC Carrier, the Seraphim tasks the Slayer to find and retrieve the Father’s life sphere from the Blood Swamps of Hell in order to return the Father to physical form. After fighting his way through the Blood Swamps, the Slayer finds and retrieves the Father’s life sphere. However, the Slayer chooses to destroy the sphere rather than hand it to the Seraphim and instead retrieves the Dark Lord’s life sphere before returning to the ARC Carrier. Despite most of the Carrier’s crew evacuating upon seeing the Dark Lord’s life sphere, a lone intern stays to help the Slayer reach Urdak assuming that the Slayer intends to resurrect and destroy the Dark Lord, which in effect will destroy all demons. Upon reaching the corrupted Urdak, the Doom Slayer fights his way to the Luminarium where anyone who has a life sphere may activate it. However, the Slayer is confronted by the Seraphim upon reaching the Luminarium’s entrance. Consumed by Urdak’s demonic corruption, the Seraphim is transformed into a demon and after a lengthy battle is ultimately defeated by the Slayer and is teleported away by the Father. Despite being warned that bringing the Dark Lord into physical form is irreversible, the Doom Slayer proceeds to summon him, and the Primeval manifests as a copy of the Slayer himself.

The Ancient Gods - Part Two takes place directly after the events of The Ancient Gods - Part One, with the Slayer and the Dark Lord in the Luminarium on Urdak. The Slayer aims his Super Shotgun at the Dark Lord and fires a shot, to which the Dark Lord informs the Slayer that no blood can be spilt in the Luminarium. He then proceeds to tell him that if he can survive, then he will challenge him to ritual combat in the city of Immora. The Dark Lord then leaves Urdak and transports the Slayer to Argent D'Nur, where he fights off the demon hordes that attack him. The Slayer then proceeds to light the Torch of Kings, as a way to inform the remaining inhabitants of Argent D'Nur and the Night Sentinels, that he is planning to go to the World Spear and acquire a wraith crystal, with which to power the Gate of Divum. During his journey, he is met by Valen who gives the Slayer his Sentinel Hammer for putting his son to rest. After acquiring the crystal, the Slayer heads back to Earth which has been invaded by demons again due to the death of the Khan Maykr and the demonic invasion of Urdak. Fighting his way through the demons, the Slayer arrives at the Gate of Divum and activates it. He is then teleported to the city of Immora, where the Dark Lord awaits. Valen and the rest of the Night Sentinels also arrive to aid the Slayer, to his surprise. The Slayer rips and tears his way through the demons in his way while the Sentinels fight outside and eventually arrives at another portal. Going through it, he is greeted by the Dark Lord, where they proceed to fight. After sustaining damage, the Dark Lord reveals to the Slayer that the Maykrs lied to him and that he is the real Father, with VEGA confirming this to be true. Moments after, the Dark Lord is ultimately defeated. With his dying breath, the Dark Lord asks if the Slayer has anything to say him before he is struck down, to which the Slayer responds with, "No." After stabbing Davoth in the chest, all demons outside of Hell disappear. However, the Slayer starts to become dizzy and eventually falls unconscious. He is then seen being sealed in his sarcophagus by three Maykrs.