Nightmare Investigators

The Nightmare Investigators were a group of specialized Reploids in Mega Man X6, issued by Reploid scientist Gate to research the remains of several zones that had been thoroughly damaged by the fall of the Eurasia Colony (during the events of Mega Man X5), where a phenomena dubbed the Zero Nightmare had been sighted.

History
Shortly after Zero's disappearance following the colony crash, Reploid scientist/researcher Gate went to investigate the crash site and discovered what he believed to be a piece of colony debris, which, after thorough analysis, ultimately granted him great power, Maverick insanity, and the desire to increase that power.

After rumors of mysterious sightings of what was later dubbed a Nightmare (and believed to be strongly related to the currently MIA Hunter Zero), Isoc (under Gate's orders) prepares a public speech in which he deems the so-called Zero Nightmare as evil and chaos-bringing, and issues eight Nightmare Investigators to research this phenomenon. In reality, this was a cover-up to allow Gate further analysis and investigation of the materials and energies that he had discovered at the crash site.

Since X didn't trust neither Isoc nor the Investigators, he went on to research the eight areas himself. Uncovering the plot behind the deployment of such Investigators, X set out to battle and defeat them all. During these events, X also discovered that Zero was alive and well, having merely gone into hiding to perform self-repair operations. Once again reunited with X, he helped him retire the Investigators and drop the veil covering the entirety of Gate's plan.

Since the Nightmare Investigators organization was created with the sole purpose of manipulating research on the Zero Nightmare, all current members had been assigned other duties and units prior to its creation. All members, including those who created the organization, were retired during the events of Mega Man X6.

Members

 * Gate
 * Isoc
 * Commander Yammark (Yellow Jewel)
 * Ground Scaravich (Green Jewel)
 * Infinity Mijinion (Red Jewel)
 * Blaze Heatnix (Green Jewel)
 * Blizzard Wolfang (Red Jewel)
 * Rainy Turtloid (Red Jewel)
 * Metal Shark Player (Red Jewel)
 * Shield Sheldon (Green Jewel)

Trivia
The jewels in all of their heads could mean the ranks that they occupy in Gate's army, red being the lowest rank (4 Mavericks), green being next highest (3 Mavericks), and yellow ( Commander Yammark).