You see a containment machine.
Notes
It looks like a Strange Apparatus.
Abilities
Unknown.
Damage Taken From Elements
Physical 
Death 
Holy 
Ice 
Fire
Energy
Earth
Drown
Location
The Orc Cult boss room under the Edron Orc Cave.
Behaviour
It doesn't move.
Strategy
Just kill it but be ready. Once it dies The Armored Voidborn will be released.