Dark Vessel
From Diablo Wiki
Dark Vessels are demons. This type of monster is likely called a Vessel, and the Dark prefix to their name denotes a particular type.
[edit] Appearance
Dark Vessels look a bit like Dark Cultists, but Vessels lean on tall crooks, and remain still in one place and ring the bells on top of their crooks, while chanting demonic verses until they transform, while Cultists are mage-like enemies who cast a variety of spells and summon demons.
Upon closer inspection, we can see that Dark Vessels have a spike on their backs. These spikes have been mentioned in the official Lore Entry for the Dark Cultists. They mutilate themselves by driving these spikes in their backs in their religious frenzy. Perhaps they show the initiation of a normal Cultist into a Dark Vessel. The lore entry has the spikes being hammered in the willing Cultists by a burly figure who may be a Dark Berserker.
[edit] In game
These human mages are commonly found standing motionless, amidst various other types of Dark enemies. Vessels are harmless in their human form, but become very dangerous melee fighters if they manage to pull a demonic entity into themselves. In that form they are known as Activated Vessels, and are ferocious fighters.
