Vessel

The Vessel (referred to as Empty Vessel until the end of Oracle, Heal Thyself) is a dormant vessel of an Eternal One used during the Zereth Mortis campaign to create a new Arbiter, specifically to serve as the Arbiter's physical body.

It initially rests in a chamber at the summit of the Resonant Peaks. During the A Means to an End chapter of the campaign, Saezurah—acting through Pocopoc—guides the Maw Walker to the Empty Vessel and teleports it back to Exile's Hollow before it and its power can be consumed by devourers.

To turn the empty host body into an Eternal One, it needs to be filled with a soul slumbering in the Crypts of the Eternal, so the Starting Over chapter of the campaign is dedicated to breaching the Crypts. Once inside, Saezurah and her Automa Scryers begin the ritual to infuse the Vessel, but the effort is sabotaged by a Darkseer Corrupter who summons the Echo of Argus so that it can infuse the Vessel and be turned into an Eternal One. The Maw Walker defeats Argus, but the Vessel is left empty. However Pelagos then offers his own soul, and Saezurah places it in the Vessel to transform him into the new Arbiter.