Nightmarch
SAGA02 - No. 7
Geography
One of the four cardinal planes of the Otherworld, Nightmarch is considered one of the safer planes, though it isn't without its dangers that lurk outside the light of the everlasting festival. Nightmarch is a plane that exists in a permanent state of pure nocturnal darkness, only illuminated by the marching parade of at least one-hundred yōkai. The parade occurs in one big continuous loop around Princess Takiyasha's Castle. Though the parade is not a consistently peaceful or orderly march, it can often break out into a bedlam of chaos.
It's unclear what exactly lies in the darkness of Nightmarch outside of the lanterns' light. It's also unclear exactly how big Nightmarch is compared to the other planes of the Otherworld. If it is relatively the same size, then it can be assumed there are numerous areas and yōkai hidden out in the abyssal expanse. It is also unknown if the whole of Nightmarch is blanked in darkness or if there are areas where natural light reaches. From what we have learned from Princess Takiyasha, there is a part of the Nightmarch controlled by Onis and another region made up exclusively of Tsukumogami or discarded objects.
While one can venture out of the parade to explore, the parade waits for no one, making it extremely easy to get lost if you lose the light of the procession. The only known, consistently illuminated landmark of Nightmarch would be Princess Takiyasha's castle.
Mythology
The realm of Nightmarch draws exclusively from Japanese folklore, with a primary focus on that of yōkai. It is possible that the unexplored areas of the Nightmarch also draw from Shinto, Japanese folklore and figures, and urban legends. It is hard to say what lies beyond the yōkai’s eternal procession.
Rulers
Nightmarch, or at the very least the Procession of 100 Demons, is overseen by the witch Princess Takiyasha. It is assumed she came into this position of power by her mastery over the frightful and powerful Gashadokuros. Though, Princess Takiyasha has clearly demonstrated her primary focus only lies within the festival, the yōkai who participate in it. This could indicate that Nightmarch has a more formal ruler, though Princess Yakiyasha did have control of the Antekey of Nightmarch.