Fly Me to The Moon

Interlude: Tide of the Moonsea

In the world of Equis, there is a force of darkness more ancient and powerful than even Discord. It is a force that is both formless and in possession of many forms. Its goals and motivations are unknown to ponykind, but its effects are unmistakable. For the most part it remains unseen, hiding in the shadows and the wild places such as the forest near Castle Everfree. However, with the help of tales told and horrors both remembered and imagined, this force has found substance in the dreams and memories of the ponies. And at the nexus of the Dreamscape, the Moon, this force coalesces into the forms of Nightmares. The force is that which plagues all of ponykind much of the time, but most especially at night: fear.

To say that the Nightmares were frightening things would be both redundant and an understatement. They were born of fear, instigated it, and fed off it in a twisted perversion of symbiosis with the denizens of Equestria. A great many of them were the stuff of day-to-day fears such as spiders and shadows. There are more intense ones, such as the fear of losing loved ones, or of being lost. Those who ruled, however, were born of great fears. By some unknown combination of popularity, power of the original figures, and intensity of the collective fear itself, it was determined that a scant few were so inherently superior to the others that their reigns were a forgone conclusion. Almost.

The Plague of Discord was the first such force to dominate the Nightmare Realm, and so long as his corporeal avatar terrorized those bound by flesh and bone, so did he reign over his empire of horrors with nigh-undisputed impunity. However, when a pair of intrepid Princesses imprisoned his corporeal counterpart in stone, so too did he lose power, making way for the Shadow King. And while this new monarch's power was not as great or widely distributed as his predecessor's, it had the unique quality of crushing nearly all hope wherever his influence reached.

That was, of course, until a new Avatar of Terror took the shadowed reaches of the Moon quite literally by storm. She started off slowly, gradually expanding her power base and filling the pony populace with a new kind of dread: paranoia. Then, as word of her counterparts' feats spread, her power among the Nightmares billowed. The Shadow King had planned to stop her before she posed a threat to him, however, he was terminally undermined by the same Princesses who had previously defeated the Avatar of Discord also defeating his living counterpart: King Sombra.

Now, with no other significant force of darkness save for the Changeling Queen to challenge her, all of her kind had no choice but to bow before their new reigning dictator: Nightmare Eclipse! And she, much like the Plague, was all too willing to allow ponykind to build up their hopes, to believe that they stood a chance of overcoming their fears. After all, in her mind, there was no victory quite so sweet as the one her enemies truly believed they had.