"Put light against light - you have nothing. Put dark against dark - you have nothing. It’s the contrast of light and dark that each give the other one meaning" - Bob RossSince the very beginning, the broad spectrums of reality have been concentrated into two divine beings, each at either end of the ultimate dichotomy: law versus chaos. First, Ashra the Sun, who seeks to foster stability and impose order on the Universe, and Boda the Moon, who undermines authority and wishes to see the Universe free of restrictions. For eons, Ashra chased Boda through the The Astral Sea, never losing ground but also unable to catch her, until finally their conflict erupted into something unexpected: the planet Cynos, and upon it, mortal life. Both Ashra and Boda felt a sense of duty to their new creation—or, perhaps, a sense of ownership. Unwilling to abandon Cynos, yet also unable to put their own rivalry aside, the chase resumed, with Sun and Moon circling the planet instead of speeding through the Astral Sea. Their dance continued until the year 0 BDB, when Ashra finally succeeded in killing Boda. As she died, her celestial body plummeted towards Cynos below, breaking up in the atmosphere and bombarding the planet with colossal chunks of lunar rock. Enormous amounts of dust, ash and debris were launched into the air, blotting out the Sun's light and dooming Cynos to an impact winter that would last for centuries to come.
Dungeons & Dragons 5e