The Ethereal and all Tau units (not Kroot, Vespid or drones) with a line of sight to him may re-roll any Morale checks. Any Tau unit joined by an Ethereal caste membeer becomes Fearless.
Building an army? Create, validate and share your list with New Recruit, army builder for Warhammer 40,000 7th Edition and many more games.
Try the builder