The Alys'aril (literally "Sanctuary of Wisdom") is the residence of the Alysaar, situated on the moon of Ehlna, on a nexus of combined energies which alter khaydarin crystals to better store memories. The complex houses the alysaar, who tend the memories. Since the Dark Templar have no preservers of their own, they used the site to store their memories. Something about the site cuts off the Khala.