This tale traces its roots to old Carthi myths, but has variations among many other cultures. It was a way to explain how and why the moon phases occur.
Long before the current era and well before the old lands sunk into the sea, Noctia bore twin daughters. Their names were Mairoma and Mihanna. They were identical in all aspects aside from coloration. Both girls had dark gray skin like their mother. Mairoma received white hair and silver eyes. Mihanna, however, had black hair and eyes. Both were regarded as equally beautiful, reflecting aspects of the night sky.
Daughters of the Night Mistress
Noctia wanted a safe place for her children to grow and play. She didn't want them roaming the stars with her. So she conjured up the moon. It appeared as a celestial body, but was also a portal to their domain. This let them watch the mortals on the planet below and have ample space of their own while being within a reasonable distance to Noctia. The face of the moon acted as their window. It also reflects the amount of light within their home. Both sisters could adjust it to their liking. Seeing they were happy, Noctia went about her business unknowing of the conflict to come.
A Place to Call Home
Mairoma was a quiet and reserved girl. She didn't like being the center of attention and found comfort in the darkness. It reminded her of their mother and the safety she brought. She wanted their realm to stay hidden among the inky blackness of the sky. The thought of mortals seeing straight into their home scared her. Mihanna felt alone and uncomfortable in the darkness. She was energetic and outgoing and loved when people could see her. Every time a mortal cooed about the moon being beautiful brought her joy. They never praised it when the light was gone. They both wanted their domain to look different. Bickering and fighting ensued.
Light VS Dark
The sisters managed to live peacefully only for a brief time. One would shift the realm gradually while the other was distracted. Once noticed, the other would retaliate and shift it back with a huff. This started as a mild back and fourth that only occurred on occasion. Over time the sisters reached a point where they fought every day. The intensity in which they moved their window also grew. As a result, the once stable tide cycle on the planet below grew unpredictable. The mortals were worried about these changes and were also concerned with the moon's constantly changing appearance. So they prayed to Noctia about the problem.
The Struggle That Shook the Tide
Their mother appeared with haste to see what their squabbling was about. With folded arms and a stern expression, she listened to each sister's complaints. She threatened to assign them star duty with her if they could not behave. After an extensive talk, they came to a compromise. Noctia couldn't create a separate dimension to split them, but they agreed an evenly spaced light cycle would work. With a little work, Noctia adjusted their domain so that the window would gradually change over the course of each month. The sisters wouldn't have to do anything and they'd each get an equal amount of preferred lighting. This stabilized the tides as the moon no longer shook intensely. Mortals were also relieved to see the predictable moon phases return to normal.