Nightmare Fuel / My Little Jamjar

• The Pale Pony. She is extremely unsettling in general.
  • Her appearance at the Equestria Games closing ceremony was especially creepy. Within the span of three minutes, she fixed her hypnotic gaze on everyone in the game, caused Kreutzer's death via massive brain hemorrhage when Kreutzer tried to read her mind, and revealed her intent to consume all of existence. And she took everything Discord could throw at her with barely a flinch.
  • What's also scarier is the fact that she used to be a Princess Twilight Sparkle. If the Setting Native Princess Twilight isn't careful, she could easily become Calice 2.0.
  • And we now find out that Calice wasn't the original Pale Pony that Star Swirl tried to defeat over a 1000 years ago. So there's a chance that there's two Pale Ponies running around. Calice and the actual goddess of death.
• Nightmare Night. Not only was Maytwi forcibly possessed by Nightmare Moon, Nightmare Moon was herself a Luna brainwashed into reverting by the Pale Pony. She was also strong enough to unleash Nightmares upon her attackers, and those ponies who were captured by the Nightmares were assimilated into her forces and turned against their friends.
• Bertha's backstory. In the past she was Megan Williams, who made a contract with Kyuubey in order to return to the world of ponies. Instead of her Ponyland, however, she ended up in Equestria as a magical girl. She befriended Celestia and Starswirl, but eventually fell to despair when her possibility of returning to Earth was lost and became a Witch. Celestia was unable to kill her, so she was then imprisoned beneath Canterlot Castle for over a thousand years.