The Deep Dweller rarely manifests in any recognizable form, but usually conveys its presence by an overwhelming fear of the deep water. When viewed by other sin-eaters it appears as a flickering whirlpool with bones occasionally surfacing in it. Erika presumes it was once male, and is old – it drowned in the 1700s or 1800s, and has almost no humanity left. Only occasionally will it speak directly to her; it relies on impressions and sensations most of the time. The Deep Dweller seems to be waiting for more Sin-Eaters to appear with growing impatience.