- Detects infiltrated units. - Inspires all Tau units on the map to fight with greater fervour. - All Tau gain a morale, health, and damage bonus while the Ethereal is alive. - Conversely, all Tau suffer a large (but temporary) morale, health, and damage penalty if the Ethereal dies. - Has many unique abilities. - Commander Unit (Unquestioned Authority). - The Ethereals (or Aun in Tau) are the leaders of Tau society. Their arrival started the unification process between the various Tau tribes and coincided with the implementation of the concept of the Greater Good. Their power over the Tau is such that an Ethereal could tell a Tau to die and that Tau would do so quickly and gladly. - The Ethereal sometimes lead the fire caste into battle to provide inspirational leadership, so the warriors can achieve more.