The universal substrate. Contains equal parts of Azus and Melera—thought and emotion at balance. Ezz is not a plane but the medium the planes hang within; Psywinds (its thought-face) and Faesong (its emotion-face) are forces within Ezz, not places. It should not be confused with Dynus, the elemental plane of physical force—Ezz is force of mind, the other force of matter.
When the Ezz is fouled, everything drawn from it is fouled with it. The Blight of Arcanus near the end of the Lost Ages was exactly this. A catastrophe poisoned the substrate, and every source that runs on it turned lethal at once: Kethic elementalism, the Psywinds, and Faesong all became deadly to work until the contamination passed. Deoric, which draws on titan material rather than the Ezz, was spared the worst. The Ezz is the one layer whose poisoning can pull three of the four sources down together.