Nightmare

The Compendium of Rockman X. 2005. is a unique virus that appeared in Mega Man X6. It was created by Gate using his research on the Sigma Virus via the DNA of , and puts Reploids into a trance where they experience harsh and dangerous illusions.
==In the Games==
===Mega Man X6===
The Nightmare appeared in Mega Man X6, acting as the main threat of the game. The game's opening depicts Gate coming across a fragment of 's body at the Eurasia crash site; a week later, he has gone mad from the sample's viral properties and begins planning to build his ideal world. This involves creating the Nightmare from his newly-acquired data.
In the , X is deployed to neutralize Mavericks at the Eurasia crash site, the first Maverick occurence since the end of the last incident. This is revealed to be due to the Nightmare, which is accompanied by the Zero Nightmare who lands the finishing blow on the D-1000. After High Max asserts dominance over X and tells him to stay out of the mystery, Isoc makes an announcement rallying Reploids across the globe to help the eight Nightmare Investigators study the Nightmare and destroy the Zero Nightmare, the alleged cause of it. X and the Hunters choose to investigate as well.
====Nightmare Phenomenon====
A is a manifestation of the Nightmare that appears in a stage, altering the stage layout in ways that usually make it more difficult for the player. There are two types of Nightmare Phenomenon: the first is the basic Nightmare, which manifests in a stage no matter what.Capcom Kanpeki Kōryaku Series #9: Rockman X6 Hisshō Kōryaku-hō. 2001.
 Nightmare Phenomenon
Name	Image	Stage 	Description
 	 	Amazon Area 	A praying mantis Nightmare that attacks by flinging its blades and summoning bug minions. If destroyed, it simply returns after a few seconds, unless the player finishes it off with Yammar Option.
 	 	North Pole Area 	Huge chunks of ice that appear out of no where, sometimes in a huge stream. They can be destroyed using Metal Anchor/Rakukojin.
 	 	Magma Area, Secret Lab 1 	Rising lava, which often appears alongside the Nightmare Snakes. It instantly kills the player on contact.
 	 	Recycle Lab, Secret Lab 2 	A ceiling-wide crusher that descends periodically. If the player is pressed between it and a surface, they are instantly killed.
 	 	Central Museum, Secret Lab 2 	Ghostly Totem Gates that warp the player to a random area, where they are pestered by flying spherical and cubical stones until they escape.
 	 	Inami Temple, Secret Lab 2 	Intense acid rain that gradually damages the player. It can only be dispelled by destroying a Weather Analyze device.
 	 	Laser Institute, Secret Lab 1	Laser cannons that operate independently, periodically shooting lasers directed at the player. They can be used to open certain doors.
 	 	Weapon Center 	The giant war machine Illumina, whose development was discontinued, is revived and attacks the player. It must be defeated by attacking its power cables.
===Nightmare S===
The second type of Nightmare Phenomenon is the Nightmare S (likely standing for Nightmare Special), which only appears depending on which stage the player last exited or cleared (save for those occurring in the Secret Lab stages). The player can tell which stages the Nightmare S affects by which boss mugshots are highlighted in red after visiting a certain stage. Multiple Nightmare S effects can be active at once, but they can only be changed one at a time, and cannot be deactivated.
 Nightmare Special Phenomenon
Name	Image	Activation Stage	Phenomenon Stage 	Description
 	 	Amazon Area 	Laser Institute, Magma Area 	Small bug Nightmares that hover near the player at a distance. They reflect all attacks, but hitting them does eventually chase them off. They can be destroyed by Yammar Option.
 	 	North Pole Area 	Recycle Lab 	Slippery ice that coats certain surfaces. It can be cleared using Ice Burst/Hyoroga.
 	 	Magma Area 	North Pole Area, Weapon Center 	Fireballs that rain down from above, damaging the player on contact. Their presence is required to open a secret frozen chamber in North Pole Area. They can be destroyed with Magma Blade/Shoenzan.
 	 	Recycle Lab 	Magma Area, Central Museum, Weapon Center	Iron blocks that appear in specific locations. They move periodically, and can be stood upon, but can also crush the player to deal heavy damage. They can be destroyed with Metal Anchor/Rakukojin.
 	 	Central Museum 	Recycle Lab, Laser Institute 	A stationary cube that can only be interacted with using Ground Dash/Sentsuizan: brown ones are destroyed, red cubes explode dangerously, black cubes slide one space forward, and purple cubes slide freely until they hit a wall.
 	 	Inami Temple 	Central Museum, Amazon Area 	Heavy wind that pushes the player when midair, represented by a light rain effect.
 	 	Laser Institute 	Inami Temple, North Pole Area 	Virtual silhouettes of X or Zero that appear at regular intervals and dash at the player, causing damage on contact. They can be dispelled with Guard Shell.
 	 	Weapon Center 	Amazon Area, Inami Temple 	Darkness that covers certain areas, save for two spotlights which intersect in the middle of the screen.
==Enemies==
Some enemies, mid-bosses, or bosses are manifestations of the Nightmare in story, but are not technically part of the Nightmare Phenomenon.
* Nightmare Virus
* Nightmare Snake
* Nightmare Pressure
===Bosses===
* Zero Nightmare
* Nightmare Mother
==References==