Klaisus

Klaisus, also spelt Kalisus and known to the Aeldari as Ulthanash’s Rest, is an ice moon, the body furthest from the sun in the Cadian System. It lies within Segmentum Obscurus and the Cadian Sector, with no coordinates recorded, and served in antiquity as an Eldar waystation toward what later became the region of Ultramar.

During the Thirteenth Black Crusade, after the destruction of Cadia, Eldrad Ulthran was among the Ynnari present on the moon who opened a webway portal in the Crone’s Claw range and guided into the webway Imperial survivors who had followed Saint Celestine, before the pursuing Black Legion retreated. Eldrad is not recorded on the planet Cadia itself.