You see Azaram's Soul.
Notes
It's part of the Grave Danger Quest, Lord Azaram's soul.
Abilities
Unknown.
Damage Taken From Elements
Physical 
Death 
Holy 
Ice 
Fire
Energy
Earth
Drown
Location
Behaviour
Unknown
Strategy
Your objective is to heal it, this can be done using Mass Healing, Ultimate Healing Runes but also by luring it over Cleansed Soul Splinters.