Saarath once was an ashkaari. He spent his days examining the philosophy of the Qun and instructing others in it. When his magic manifested, he became a saarebas under the command of Viddasala. He was involved in the study of the Veil on her orders, a part of the Qunari plan called "Dragon's Breath".
The Inquisitor catches a glimpse of Saarath and Viddasala entering an eluvian in the Gully within Elven Ruins. If Cole is present, he explains that Saarath can't be far from her lest he feels pain.
In the Shrine to the Dread Wolf Viddasala orders Saarath to attack the Inquisitor, but he manages to break free of his leash in the course of the fight and flees.
Saarath later confronts the Inquisitor in a secluded area within the Shrine where he guards a single eluvian. His mask is now half-broken, magic crackles around him and he summons demons to aid him in battle. The Inquisitor weakens Saarath and then uses the Anchor to kill him.