You see The Astral Source
Notes
It also exists in a distorted form, The Distorted Astral Source. Part of the Forgotten Knowledge Quest.
Abilities
Melee (0-401+)
Mana Drain AoE (0-87+)
Self-Healing (0-467+) Mass Healing heals Animated Swords (0-1200+) Physical Beam (0-1700)Damage Taken From Elements
Physical 
Death
Holy
Ice
Fire
Energy
Earth
Location
Final boss room of the Forgotten Knowledge Quest.
Behaviour
Unknown
Strategy
Unknown