The light of Xaryxis has nourished the Xaryxian Empire for millennia, serving as a wellspring for the magical power that the astral elves of Xaryxispace use to sustain their empire. A thousand years ago, the star's light began to fade, threatening the elves' prosperity, so Emperor Xavan turned the dying star into a parasite that leaches the life from worlds using crystal seeds harvested from the star.
After the elves select a suitable host world, ships known as star moths release hundreds of astral seeds into the planet's atmosphere. The seeds fall from the sky and bury themselves in the ground and the oceans of the world. After the astral seeds take root, they produce enormous crystalline vines. The tendrils of these vines extend deep into the world and draw life energy from it. Once the vines have sapped a world of its energy, a process that can take months, they send out a bright beam of light that travels back to Xaryxis, temporarily replenishing the star's radiance and leaving the host world a barren husk.
Although Xaryxis shines brilliantly after each replenishment, it isn't long before the light of Xaryxis begins to wane once more, presaging the doom of another world.
Once astral seeds have taken root on a host world, there is no easy way to stop the transformation—the vines are too thick and too numerous to be uprooted. Destroying the star Xaryxis, which acts as a lodestone for the astral seeds, is the only way to free a world from their grip. If the star goes dark, the crystal vines release their stored energy back into the host world, shrivel, and die.