The First Child of Light & The Second Blinding

Celestial / Cosmic

Light — believed to be a god walking among mortals — began appearing in each of the 23 surviving cities, one per year. In every visit, He chose a single child, declaring them the first Blessed of their dome and commanding them to carry His spark to the Holy Altar, for the domes were beginning to fail. This marked the beginning of the Cult of Light.
Their sacrifice rekindled the Sun for one year from there on.

He told of His sacred word, the Covenant of Dawn, and created the founding myth for dome societies, namely that should one city fail to send a child of light in the alloted year, the sun would extinguish again. He anchored then the system of castes, brought each city the Gestalt, a device able to assign a caste to each 5-year old and also detect a new child of light each time it was needed.

The sun was relit in a blinding event that gripped the remaining survivors of the world.

Each year, the dimming of the sun remembered every one that the life offered by Light should be taken for granted and consolidated the faith in this god, but also in his 2 other parts. Like a holy trinity, 3 distinct gods, but also one and the same according to this new faith, were watching over the world.

Dark - the moon - and the one that caused the destruction of the old world.
Light - the sun - and the god that protects the domes of light.
Twilight,the god that mediates between both of them and keeps both their powers at bay to create a semblance of a liveable belt going around the globe, caught in eternal twilight.

Thus began the Sacred Cycle of Renewal.