Nightmare of Qalec, the Sniper

The Nightmare of Qalec, the Sniper is the Nightmare of the Psion rebel, Qalec. After his attempt on the life of Commander Zavala ended in failure, he was publicly disgraced and executed at the hands of Empress Caiatl. He was later recreated as a Nightmare by the Lunar Pyramid, and would serve the will of Emperor Calus.

Gameplay
The Nightmare of Qalec spawns in a hidden room in the Royal Pools area of the Derelict Leviathan. When you are exploring the area, there is a chance that you will receive a message saying "A red laser dot briefly passes over your Ghost...". Go to the bathhouse on the far right side, then drop down through a hole in the far left corner, surrounded by Egregore. This will lead into a room where you will see a Nightmare Incendior immediately upon entering, with multiple other enemies in the connected corridor. Engaging them will cause the Nightmare of Qalec to spawn in the room on the other end of said corridor, and you will have a limited amount of time defeat it before it disappears.

Qalec's Nightmare is highly resilient, and takes very little damage from any attacks. Like other Psions, it is also incredibly agile and can move around the room quickly. Several other Nightmare reinforcements will arrive to assist their commander, consisting of Legionaries, Psions and War Beasts, which will spawn continuously. Both the boss and its forces are extremely powerful and can kill you very fast, so it is advised that you focus on the lesser enemies whenever they arrive. They will also drop Unstable Essence upon death, which will allow you to deal increased damage to Nightmares. If you manage to eliminate the Sniper before time runs out, you will be awarded the 'Drainage' Triumph, and you may collect loot from the chest that spawns.

Trivia

 * The message indicating that the Nightmare of Qalec is in the area, reading "A red laser dot briefly passes over your Ghost...", is a reference to the Psion shooting Zavala's Ghost, Targe, with a Light-suppressing device at the signing of the peace treaty.
 * Despite Qalec being seen wearing Imperial Cabal Psion armor in the cutscene after Proving Grounds Strike, his Nightmare appears to don the colors of Calus's Loyalists.

List of appearances

 * Destiny 2
 * Season of the Haunted