The health of Aerbax's Shadow was increased from 500,000 to 1,000,000 Health in the ??? patch.
Physical attacks from Aerbax's Shadow consist of hollow lightning. They will ignore all banes and life protections.
Aerbax's Shadow tells you, "I am Aerbax. I am afraid that I must end some of you in a moment. Take comfort in the knowledge that you have facilitated a great awakening of all sentient races on Dereth."