Day and Night

The Day and Night is a dimension in which can be found.

Appearance
The Day and Night is seemingly an infinite void divided by a horizon into a dark, nightlike part and a bright, daylike part. The physics of the dimension behaves strangely, with fish swimming in the air that a human can breathe and the floor creating waterlike ripple effects while Emma walks on its surface.

Cuvitidala
The easiest known entryway to the Day and Night is through the Cuvitidala. However, it is not the "correct" entryway, but only a vision, and upon entering, Emma is prompted by Him to go to the proper entrance.

Seven Walls
The proper entrance, the Seven Walls is much more challenging. Only two individuals, Julius Ratri and Emma, are known to have successfully made it to the Demon King and back through the Seven Walls.

Emma
Emma visits the Day and Night on two occasions, once through each entrance.

Julius Ratri
Julius Ratri entered the Day and Night in order to forge the original Promise.

The Demon King
The Demon King is the most notable inhabitant and the reason most, Emma included, seek to come to the Day and Night.

The Dragon of Cuvitidala
Spoken of in legends, the Cuvitidala Dragon is often seen alongside the Demon King. It does little but fly around and has no clear role as of yet.

Fish
Odd, fish-like fauna inhabit the Day and Night and are seen swimming around the Demon King.