Nightmare Fuel / Mega Man X6

• Sigma... just Sigma. After the events of X5, Sigma was essentially dead; after spreading himself so thin infecting the entire globe, he was barely hanging onto his sense of self before the Hunters defeated him. Then Gate comes along and decides he could use Sigma as a final gambit weapon, gathering up his shattered mind and essentially pouring it into an old, wrecked body. It goes about as well as you'd expect; Sigma annihilates Gate as soon as he's awoken, and after our heroes destroy the slapdash zombie body Gate left him in, he goes completely off his rocker. It's scary to see the once eloquent Sigma start frothing and gibbering, nothing on his mind but murder.
  • And take a look at his Character Portrait: It is not a standard mugshot with animated mouth-flaps like every other character. It is a still, blurry and completely purple close up to Sigma's face, staring directly to the player with a Slasher Smile.
• The Nightmare Virus. Unlike other viruses in the series, which merely skew a Reploid's moral view, this one is literally a zombie plague- when a Reploid is infected, it destroys their mind and even their DNA, commandeering the corpse to attack others.
  • You can see it infect a Reploid in-game if you're not quick to destroy a Virus enemy before it grabs hold of an Injured Reploid. The virus completely disfigures the Reploid, turning their skin green and rendering them mindlessly aggressive. And to ram the point home, if a Reploid dies this way, they're gone forever, listed in game as either dead (if you kill them) or missing (if you leave the zombie alive).
• The scenery in Gate's Lab is strange to begin with and quickly gets scarier. You begin to see statues in the background that look like robotic demons and angels; and as you progress through the levels, the angels begin to lose parts while the demons start gaining them. In the final room in which you face Sigma, the angel is in tatters with a bare metal skeleton... and the demon has musculature and weaponry, and is roaring at the sky like it's about to break free. Luckily they're just statues... or at least you never fight them.
• The Zero Nightmare is just as messed up as the virus it spreads. A discoloured, insane copy of Zero created by Gate as a scapegoat for his investigation, it wavers constantly between relative eloquence and insane gibbering on par with Sigma's example above. Put yourself in the shoes of X and imagine how it must feel to be confronted by the ghost of your old friend, pointing their saber at you and declaring you a Maverick; or worse, simply screaming nonsense.
• The Nightmare Mother boss. Literally two giant, pulsating blocks of infectious DNA, their only distinguishing feature being a metal, HAL 9000- like eyeball staring at the player.
• What happens to Isoc isn't exactly clear; X/Zero find his body in Gate's Lab, completely wiped of any mind or soul. He doesn't show any signs of damage either. If you don't subscribe to the Isoc-is-Wily theory, you have to wonder... what in the hell happened to him?
• The entire scenario of X6 is Nightmare Fuel for Alia. She is revealed to have been one of Gate's colleagues in the past... as well as one of the conspirators that destroyed his creations after he refused to deactivate them, albeit she was deceived into doing so. Seeing all those creations come Back from the Dead must be stressful enough... imagine if they learned just who it was that killed them in the first place.
• It's also Nightmare Fuel for Zero. Especially after the events of X5, he knows exactly how dangerous he (and anything related to him) can be. And then he discovers that Gate has been gleefully toying around with a piece of his DNA. Is it any wonder that one of the endings has him seal himself away for a century?

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