Depthswalker class was gifted to Achaea by Tenith'oru in a poignant moment of loss and spite. A both selfish and selfless act in order to ensure the doom of the Tsol'teth race.
Sharing the Tsol'teth secrets of Shadowmancy and the research trees of Terminus with the world, ex-Tenith'oru completed the knowledge with his own studies of Aeonics. Perfected by he and his protege Kosuira, the Depthswalker is capable of altering time to affect the world around them.
In order to begin their study and access the research laboratory to unlock the powers offered by Terminus, the wielder of Time must first work out how to seek Kosuira, the only known protege of Tenith'oru whose death upon the Sangre Plains in the Sarapin of 727 AF prompted the distribution of such guarded knowledge.