You see a demon
Notes
It's a Goblin with demon outfit and name. They turn to dead goblins when they die.
Abilities
Damage Taken From Elements
Physical 
Death
Holy
Ice
Fire
Energy
Earth
Location
Pits of Inferno (Bazir's throneroom), Oasis Tomb.
Behaviour
They run away when they are in red health.
Strategy
The same as a normal Goblin