Spider Mastermind (Doom 2016)

The Spider Mastermind, also referred to by the demons' scriptures as the Aranea Imperatrix and the form of the Dread Widow, is the final boss of Doom (2016).

Tactical analysis
As the final boss of the game, the Spider Mastermind is suitably dangerous with a wide variety of attacks to keep the player on their toes. For her primary weapon, the Mastermind sports a deadly Argent plasma gun, and will fire off rapid fan-like bursts of shots. Throughout the fight, the Mastermind will sweep the area with lasers at various altitudes, first counterclockwise, then clockwise. Should the player get too close, she will swipe at them with her enormous clawed legs.

Unwilling to simply sit still and act as target practice, the Mastermind will shunt herself to the side or flip over and walk upside down if she feels the player has too much of a clear shot.

As she takes more damage, the Mastermind will begin new attacks. To further limit the player's maneuverability she can fire clusters of glowing bombs. Occasionally she can channel her enormous brain and electrocute the ground, forcing the player to climb atop the stone pillars to escape massive damage. The player should watch the Mastermind closely once they've climbed to safety, as the Mastermind can cause spikes to erupt on the pillars or follow by grabbing a giant stone block with her telekinesis and send it speeding their way.

Once she has taken critical damage, the Mastermind will stumble. Now unable to stand, the Mastermind will struggle and crawl to line up her laser cannons or pick up more stone blocks, but for the most part the fight will almost certainly end in the player's favor at this point. Once reduced to zero health, the Mastermind will collapse, setting the player up for the final glory kill of the game.

Umbral compendium
The Spider Mastermind was spoken of in a demonic prophecy contained in a compendium found by the UAC in the Umbral Plains during the first Lazarus tethering operation, designation MTC 2146/351. The tome, found in the crypt of a destroyed tower of unknown construction (codenamed PL E2M8), spoke cryptically of the Aranea Imperatrix as being the union between the master of the fourth age of Hell and the "key holder", referred to only as being a female with no further clarification. The form of the Aranea Imperatrix is said to be carried in the mind of all demons, to be fed with the blood of those who have fallen in battle, and to be made with bones of rock, iron, steel, and sinew. The prophecy refers to the entity as a "god to rule all other gods," and promises that it will be imbued with the power of a dark priest and will banish the heretics of the Penumbral Plain.

Genesis
The form of the Spider Mastermind is granted to Olivia Pierce by the demons in exchange for her attempts to rip open a portal to Hell. When the Doom Slayer finally finds her deep within Argent D'Nur, she seems distraught, saying only, "They promised me so much..." No sooner than she utters these words, however, she is pulled down into the pool of blood on which she stands, and then re-emerges almost immediately in her new form.

From the manner in which the "Aranea Imperatrix" is spoken of by the demons in their codices and tablets, it is implied that Olivia does not have full control over the beast (and possibly none at all, due to her weak will and selling out of the UAC facilities on Mars), but this does not limit the newly-formed demon's animosity for the Doom marine in any way.