Nightmare of Dominus Ghaul

"The Red War saw so many lives lost. Saw the Light taken away so easily. In Light, there is only weakness."

- The Darkness to the Guardian, upon banishing the Nightmare of Ghaul

The Nightmare of Dominus Ghaul is the Nightmare of the late Dominus of the Red Legion: Ghaul. It serves as a manifestation of the Guardian's fears and trauma—created by the Lunar Pyramid—and is used to taunt them by reminding them of how easily the Light was taken from them. Years later, it would reemerge aboard the Derelict Leviathan to torment Empress Caiatl, who would descend into the Underbelly of the vessel in an attempt to confront it.

Shadowkeep
The Nightmare of Dominus Ghaul's appearance in Shadowkeep appears to have served as merely a functionary, as it does not speak or otherwise socially interact with the Guardian. It exists only as an obstacle to progression, whether that was entrance to the Lunar Pyramid, or as the focus of a Nightmare Hunt instructed by Eris Morn.

Season of the Haunted
In Season of the Haunted, the Nightmare of Dominus Ghaul takes on a speaking role, taunting Empress Caiatl over the current situation of the Cabal. As a beacon of the martial might of the Cabal, the Nightmare continually pressed Caiatl on her actions since his death, such as fleeing Torobatl, allying with the Guardians (which it sees as subservience), and more. It professed a strong belief that everything Ghaul had done to shape Caiatl as a warrior had gone to waste, with Caiatl struggling to surpass this opinion. Eventually, Caiatl looks past the domineering and suicidal course that the Nightmare contends the Cabal should continue upon, and transforms the Nightmare of Dominus Ghaul into a Memory of Dominus Ghaul. Thus, everything it stands for became a reminder of how the Cabal shouldn't act in the future of its civilization.

The Memory left several psychic imprints across the Leviatan, which it used to converse with the Guardian. It then lent aid against Emperor Calus, during the final confrontation with him in the Chantry of the Darkest Hour. Here, the Guardian and Empress Caiatl also fought a Fading Nightmare of Gaul, which they ultimately defeated. The Memory of Ghaul then dissipated, alongside the other Memories.

Gameplay
The Nightmare of Dominus Gaul fights much like its living counterpart, fought in the mission Chosen. He will briefly roam on the ground, firing his Projection Rifle and using his Quake on close targets, but will soon channel Light-imitating powers, lifting himself in the air, and either shoot burning Solar empowered blades with Solar Slicer, charge a slowing dome of Void energy, or launch crackling lingering bursts of Arc.

It is briefly encountered at the end of the mission A Mysterious Disturbance, where it will be immune to damage.

It is then fought inside the Lunar Pyramid, in a recreation of the final battle of the Red War. It will fight much like described above, and activate its immunity once below half health, requiring the player to kill Major Nightmare Cabal that appear in the arena in order to make him vulnerable again.

He is then encountered as the target of the Nightmare Hunt: Rage, where it confronts the fireteam in the Chamber of Night. Once brought down a third of its health, he will become immune and summon Major Nightmare Cabal. At the last third of its health, he will also summon several Psions with powerful Solar Absorption Shields, though only the Nightmare Cabal must be killed to make him vulnerable.

He is also fought in the Sever - Rage and Sever - Resolve missions, where it will be supported by many Loyalists. The arena is small, but offers plenty of cover, and the player will be able to acquire the Scythe every third of his health, making dealing with him and his troops easier.

Finally, the Nightmare is fought in the mission Catharsis, as the Fading Nightmare of Ghaul, alongside the Fading Nightmare of Kethiks and several Loyalists and Scorn. It will be protected by its Nightmare Immunity, which can only be broken with the Scythe. If the other Nightmare still lives when he is killed, Calus will begin his attack, which can only be avoided by entering Caiatl's shield. If he is the last Nightmare standing, his death will bring the battle to an end.

List of appearances

 * Destiny 2
 * Shadowkeep
 * Season of the Haunted